Don't crash on second resolve or reject in PromiseImpl. (facebook#20303)

Summary:
Promise semantics per JS should allow calling resolve or reject repeatedly without crashing. Only the first one should do anything, but others should be allowed. This change fixes the Java bridge for Android. A separate change is needed for iOS.

Issue facebook#20262
Pull Request resolved: facebook#20303

Differential Revision: D13396975

Pulled By: cpojer

fbshipit-source-id: 81f14f73654fa7c44e043f574a39fda481ace44b

Author: esprehn

ReactAndroid/src/main/java/com/facebook/react/bridge/PromiseImpl.java

@@ -28,6 +28,8 @@ public PromiseImpl(@Nullable Callback resolve, @Nullable Callback reject) {
   public void resolve(Object value) {
     if (mResolve != null) {
       mResolve.invoke(value);
+      mResolve = null;
+      mReject = null;
     }
   }
 
@@ -67,5 +69,7 @@ public void reject(String code, String message, @Nullable Throwable e) {
       // TODO(8850038): add the stack trace info in, need to figure out way to serialize that
       mReject.invoke(errorInfo);
     }
+    mResolve = null;
+    mReject = null;
   }
 }