RemoteServiceGrpc.RemoteServiceStub getStub() {
        return RemoteServiceGrpc.newStub(getChannel());
    }
Get channel state by the true value of request connection.

@return a channel when the state to be ready
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/GRPCRemoteClient.java