Addressed CR comments

Author: yojagad

src/proto/FunctionRpc.proto

@@ -263,13 +263,13 @@ message InvocationRequest {
 // Host sends ActivityId, traceStateString and Tags from host
 message RpcTraceContext {
 	// This corresponds to Activity.Current?.Id
-	string Traceparent = 1;
+	string trace_parent = 1;
 
 	// This corresponds to Activity.Current?.TraceStateString
-	string Tracestate = 2;
+	string trace_state = 2;
 
 	// This corresponds to Activity.Current?.Tags
-	map<string, string> Attributes = 3;
+	map<string, string> attributes = 3;
 }
 
 // Host requests worker to cancel invocation