Give a name to the ReactContext thread

Summary: tired of looking around for this thread. named it "create_react_context"

Differential Revision: D9664714

fbshipit-source-id: 8839b5724fe2516fc46de3dd40971c52a5a8168f

Author: ayc1

ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManager.java

@@ -905,6 +905,7 @@ private void runCreateReactContextOnNewThread(final ReactContextInitParams initP
 
     mCreateReactContextThread =
         new Thread(
+            null,
             new Runnable() {
               @Override
               public void run() {
@@ -958,7 +959,8 @@ public void run() {
                   mDevSupportManager.handleException(e);
                 }
               }
-            });
+            },
+            "create_react_context");
     ReactMarker.logMarker(REACT_CONTEXT_THREAD_START);
     mCreateReactContextThread.start();
   }