[VOL-3117] Read KV store data path prefix from an environment variable

- voltha-lib-go reads the KVStoreDataPrefix from env variable, so removed the command-line flag in voltha-go
- also removed unused corepair topic flag
Change-Id: Ibe8403bf187126b587a92cd9c58aa6d923f84cd0
diff --git a/rw_core/core/device/agent_test.go b/rw_core/core/device/agent_test.go
index 29d8062..cd49681 100755
--- a/rw_core/core/device/agent_test.go
+++ b/rw_core/core/device/agent_test.go
@@ -112,7 +112,7 @@
 
 func (dat *DATest) startCore(inCompeteMode bool) {
 	cfg := config.NewRWCoreFlags()
-	cfg.CorePairTopic = "rw_core"
+	cfg.CoreTopic = "rw_core"
 	cfg.DefaultRequestTimeout = dat.defaultTimeout
 	cfg.KVStorePort = dat.kvClientPort
 	cfg.InCompetingMode = inCompeteMode
@@ -129,8 +129,7 @@
 		Host:                    cfg.KVStoreHost,
 		Port:                    cfg.KVStorePort,
 		Timeout:                 cfg.KVStoreTimeout,
-		LivenessChannelInterval: cfg.LiveProbeInterval / 2,
-		PathPrefix:              cfg.KVStoreDataPrefix}
+		LivenessChannelInterval: cfg.LiveProbeInterval / 2}
 	dat.kmp = kafka.NewInterContainerProxy(
 		kafka.InterContainerHost(cfg.KafkaAdapterHost),
 		kafka.InterContainerPort(cfg.KafkaAdapterPort),
@@ -142,13 +141,13 @@
 	proxy := model.NewDBPath(backend)
 	dat.adapterMgr = adapter.NewAdapterManager(proxy, dat.coreInstanceID, dat.kClient)
 
-	dat.deviceMgr, dat.logicalDeviceMgr = NewManagers(proxy, dat.adapterMgr, dat.kmp, endpointMgr, cfg.CorePairTopic, dat.coreInstanceID, cfg.DefaultCoreTimeout)
+	dat.deviceMgr, dat.logicalDeviceMgr = NewManagers(proxy, dat.adapterMgr, dat.kmp, endpointMgr, cfg.CoreTopic, dat.coreInstanceID, cfg.DefaultCoreTimeout)
 	dat.adapterMgr.Start(context.Background())
 	if err = dat.kmp.Start(); err != nil {
 		logger.Fatal("Cannot start InterContainerProxy")
 	}
 
-	if err := dat.kmp.SubscribeWithDefaultRequestHandler(kafka.Topic{Name: cfg.CorePairTopic}, kafka.OffsetNewest); err != nil {
+	if err := dat.kmp.SubscribeWithDefaultRequestHandler(kafka.Topic{Name: cfg.CoreTopic}, kafka.OffsetNewest); err != nil {
 		logger.Fatalf("Cannot add default request handler: %s", err)
 	}
 
diff --git a/rw_core/core/device/logical_agent_test.go b/rw_core/core/device/logical_agent_test.go
index 77c4b7c..2649ee4 100644
--- a/rw_core/core/device/logical_agent_test.go
+++ b/rw_core/core/device/logical_agent_test.go
@@ -454,7 +454,7 @@
 
 func (lda *LDATest) startCore(inCompeteMode bool) {
 	cfg := config.NewRWCoreFlags()
-	cfg.CorePairTopic = "rw_core"
+	cfg.CoreTopic = "rw_core"
 	cfg.DefaultRequestTimeout = lda.defaultTimeout
 	cfg.KVStorePort = lda.kvClientPort
 	cfg.InCompetingMode = inCompeteMode
@@ -471,8 +471,7 @@
 		Host:                    cfg.KVStoreHost,
 		Port:                    cfg.KVStorePort,
 		Timeout:                 cfg.KVStoreTimeout,
-		LivenessChannelInterval: cfg.LiveProbeInterval / 2,
-		PathPrefix:              cfg.KVStoreDataPrefix}
+		LivenessChannelInterval: cfg.LiveProbeInterval / 2}
 	lda.kmp = kafka.NewInterContainerProxy(
 		kafka.InterContainerHost(cfg.KafkaAdapterHost),
 		kafka.InterContainerPort(cfg.KafkaAdapterPort),
@@ -484,7 +483,7 @@
 	proxy := model.NewDBPath(backend)
 	adapterMgr := adapter.NewAdapterManager(proxy, lda.coreInstanceID, lda.kClient)
 
-	lda.deviceMgr, lda.logicalDeviceMgr = NewManagers(proxy, adapterMgr, lda.kmp, endpointMgr, cfg.CorePairTopic, lda.coreInstanceID, cfg.DefaultCoreTimeout)
+	lda.deviceMgr, lda.logicalDeviceMgr = NewManagers(proxy, adapterMgr, lda.kmp, endpointMgr, cfg.CoreTopic, lda.coreInstanceID, cfg.DefaultCoreTimeout)
 	if err = lda.kmp.Start(); err != nil {
 		logger.Fatal("Cannot start InterContainerProxy")
 	}
diff --git a/rw_core/core/device/manager.go b/rw_core/core/device/manager.go
index 17ac266..c7af54a 100755
--- a/rw_core/core/device/manager.go
+++ b/rw_core/core/device/manager.go
@@ -60,11 +60,11 @@
 }
 
 //NewManagers creates the Manager and the Logical Manager.
-func NewManagers(dbPath *model.Path, adapterMgr *adapter.Manager, kmp kafka.InterContainerProxy, endpointMgr kafka.EndpointManager, corePairTopic, coreInstanceID string, defaultCoreTimeout time.Duration) (*Manager, *LogicalManager) {
+func NewManagers(dbPath *model.Path, adapterMgr *adapter.Manager, kmp kafka.InterContainerProxy, endpointMgr kafka.EndpointManager, coreTopic, coreInstanceID string, defaultCoreTimeout time.Duration) (*Manager, *LogicalManager) {
 	deviceMgr := &Manager{
 		rootDevices:             make(map[string]bool),
 		kafkaICProxy:            kmp,
-		adapterProxy:            remote.NewAdapterProxy(kmp, corePairTopic, endpointMgr),
+		adapterProxy:            remote.NewAdapterProxy(kmp, coreTopic, endpointMgr),
 		coreInstanceID:          coreInstanceID,
 		dbPath:                  dbPath,
 		dProxy:                  dbPath.Proxy("devices"),
diff --git a/rw_core/core/device/remote/adapter_proxy.go b/rw_core/core/device/remote/adapter_proxy.go
index f4579ef..4cbb363 100755
--- a/rw_core/core/device/remote/adapter_proxy.go
+++ b/rw_core/core/device/remote/adapter_proxy.go
@@ -18,6 +18,7 @@
 
 import (
 	"context"
+
 	"github.com/opencord/voltha-lib-go/v3/pkg/kafka"
 	"github.com/opencord/voltha-lib-go/v3/pkg/log"
 	ic "github.com/opencord/voltha-protos/v3/go/inter_container"
@@ -29,22 +30,22 @@
 type AdapterProxy struct {
 	kafka.EndpointManager
 	deviceTopicRegistered bool
-	corePairTopic         string
+	coreTopic             string
 	kafkaICProxy          kafka.InterContainerProxy
 }
 
 // NewAdapterProxy will return adapter proxy instance
-func NewAdapterProxy(kafkaProxy kafka.InterContainerProxy, corePairTopic string, endpointManager kafka.EndpointManager) *AdapterProxy {
+func NewAdapterProxy(kafkaProxy kafka.InterContainerProxy, coreTopic string, endpointManager kafka.EndpointManager) *AdapterProxy {
 	return &AdapterProxy{
 		EndpointManager:       endpointManager,
 		kafkaICProxy:          kafkaProxy,
-		corePairTopic:         corePairTopic,
+		coreTopic:             coreTopic,
 		deviceTopicRegistered: false,
 	}
 }
 
 func (ap *AdapterProxy) getCoreTopic() kafka.Topic {
-	return kafka.Topic{Name: ap.corePairTopic}
+	return kafka.Topic{Name: ap.coreTopic}
 }
 
 func (ap *AdapterProxy) getAdapterTopic(deviceID string, adapterType string) (*kafka.Topic, error) {