VOL-4032 documentation for Heartbeat RPC and Events handling

Change-Id: I643b892ab8ee67910ed21e3a0ac702ebd7e768e7
diff --git a/docs/EventsMetrics.md b/docs/EventsMetrics.md
index 89c1e22..e482365 100644
--- a/docs/EventsMetrics.md
+++ b/docs/EventsMetrics.md
@@ -28,3 +28,5 @@
 }
 ```
 Note: The on-demand metrics query using the API `GetMetric` would be passed back over GRPC and not over the kafka bus.
+
+The device shall not locally persist the events across the reboot. The NEM implementations are expected to purge all the unresolved events (events for which the corresponding RECOVERED events have not yet been sent) on the device reboot, as the device shall detect and report the events afresh after the reboot.
diff --git a/docs/ManagingDevice.md b/docs/ManagingDevice.md
index f6f545a..ef66776 100644
--- a/docs/ManagingDevice.md
+++ b/docs/ManagingDevice.md
@@ -49,6 +49,7 @@
 In the call to this RPC, both the `name` and the `uuid` of the component need to be passed in the `HWComponentInfoGetRequest`.
 
 The `name` has to be unique for each of the components of the hardware and the `uuid` has to be universally unique. Implementation of Device Manager need to ensure this. Both of these two attributes are generated by the Device Manager.
+
 ## SetHWComponentInfo
 ``` protobuf
 // Sets the permissible attributes of a HW component
@@ -58,4 +59,11 @@
 
 Using this RPC, it is possible to modify the `name` of a component, and the Device Manager has to ensure that the name is unique, else it should return an error for this RPC. Although the `name` can be modified, it is recommended that NEM implementations do not do this because Device Managers and take advantage of this and come up with efficient implementations.
 
+## HeartbeatCheck
+``` protobuf
+// Performs the heartbeat check
+rpc HeartbeatCheck(google.protobuf.Empty) returns (Heartbeat);
+```
+This RPC is used to perform the hearbeat check for the connectivity. When the gRPC server streaming is used for conveying the Events and Metrics to external systems, on the connectivity break and reestablishment, the server streaming RPCs need to be established again.
+