Update rpc-caller header of grpc (#824)

This might be a breaking change since it updates the rpc-caller header of grpc from uber-java to be a variable from clientOptions.
If there is any dependency on the value uber-java, updates the corresponding clientOptions value to be uber-java

Author: Shaddoll

src/main/java/com/uber/cadence/internal/compatibility/proto/serviceclient/GrpcServiceStubs.java

@@ -106,7 +106,7 @@ final class GrpcServiceStubs implements IGrpcServiceStubs {
     headers.put(FEATURE_VERSION_HEADER_KEY, Version.FEATURE_VERSION);
     headers.put(CLIENT_IMPL_HEADER_KEY, CLIENT_IMPL_HEADER_VALUE);
     headers.put(RPC_SERVICE_NAME_HEADER_KEY, options.getServiceName());
-    headers.put(RPC_CALLER_NAME_HEADER_KEY, CLIENT_IMPL_HEADER_VALUE);
+    headers.put(RPC_CALLER_NAME_HEADER_KEY, options.getClientAppName());
     headers.put(RPC_ENCODING_HEADER_KEY, "proto");
     if (!Strings.isNullOrEmpty(options.getIsolationGroup())) {
       headers.put(ISOLATION_GROUP_HEADER_KEY, options.getIsolationGroup());