VOL-4284 simplify command line arg specification

Change-Id: Icc96dbf8ef1c06a4976c54fa53ce79f55f715e6a
diff --git a/rw_core/core/api/grpc_nbi_handler_test.go b/rw_core/core/api/grpc_nbi_handler_test.go
index 98e1d04..622257d 100755
--- a/rw_core/core/api/grpc_nbi_handler_test.go
+++ b/rw_core/core/api/grpc_nbi_handler_test.go
@@ -95,7 +95,8 @@
 func (nb *NBTest) startCore(inCompeteMode bool) {
 	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
 	defer cancel()
-	cfg := config.NewRWCoreFlags()
+	cfg := &config.RWCoreFlags{}
+	cfg.ParseCommandArguments([]string{}) // sets defaults
 	cfg.CoreTopic = "rw_core"
 	cfg.EventTopic = "voltha.events"
 	cfg.DefaultRequestTimeout = nb.defaultTimeout
diff --git a/rw_core/core/device/agent_test.go b/rw_core/core/device/agent_test.go
index 63eb7df..e3716a7 100755
--- a/rw_core/core/device/agent_test.go
+++ b/rw_core/core/device/agent_test.go
@@ -117,7 +117,8 @@
 }
 
 func (dat *DATest) startCore(ctx context.Context) {
-	cfg := config.NewRWCoreFlags()
+	cfg := &config.RWCoreFlags{}
+	cfg.ParseCommandArguments([]string{})
 	cfg.CoreTopic = "rw_core"
 	cfg.EventTopic = "voltha.events"
 	cfg.DefaultRequestTimeout = dat.defaultTimeout
diff --git a/rw_core/core/device/logical_agent_test.go b/rw_core/core/device/logical_agent_test.go
index 96729a2..8114dd0 100644
--- a/rw_core/core/device/logical_agent_test.go
+++ b/rw_core/core/device/logical_agent_test.go
@@ -136,7 +136,8 @@
 }
 
 func (lda *LDATest) startCore(ctx context.Context, inCompeteMode bool) {
-	cfg := config.NewRWCoreFlags()
+	cfg := &config.RWCoreFlags{}
+	cfg.ParseCommandArguments([]string{})
 	cfg.CoreTopic = "rw_core"
 	cfg.EventTopic = "voltha.events"
 	cfg.DefaultRequestTimeout = lda.defaultTimeout
diff --git a/rw_core/core/device/manager_test.go b/rw_core/core/device/manager_test.go
index 23968b5..1594b6e 100644
--- a/rw_core/core/device/manager_test.go
+++ b/rw_core/core/device/manager_test.go
@@ -79,7 +79,8 @@
 }
 
 func (dat *DATest) startCoreWithCustomICProxy(ctx context.Context, kmp kafka.InterContainerProxy) {
-	cfg := config.NewRWCoreFlags()
+	cfg := &config.RWCoreFlags{}
+	cfg.ParseCommandArguments([]string{})
 	cfg.CoreTopic = "rw_core"
 	cfg.EventTopic = "voltha.events"
 	cfg.DefaultRequestTimeout = dat.defaultTimeout