Don't wait so long to check if stream is running (to avoid missing audio once 'resume' is called); 2ms is consistent with write wait time as well

examples/common-grpc.cpp

@@ -126,7 +126,7 @@ void audio_async::grpc_handler_thread() {
                 resume();
             }
         } else {
-            std::this_thread::sleep_for(std::chrono::milliseconds(100));
+            std::this_thread::sleep_for(std::chrono::milliseconds(2));
         }
     }
 }