Android: Avoid throwing error when initManager is called twice

Made changes to prevent IllegalStateException from being thrown when initManager is called more than once. Rather than throwing an error, the code now logs a message and simply returns without further action.

src/android/FileTransferBackground.java

@@ -152,8 +152,10 @@ public boolean execute(String action, JSONArray args, final CallbackContext call
     }
 
     private void initManager(String options, final CallbackContext callbackContext) throws IllegalStateException {
+        // Calling this twice isn't a huge deal. Let's not make it one.
         if (this.ready) {
-            throw new IllegalStateException("initManager was called twice");
+            logMessage("initManager was called after it was already initialized");
+            return;
         }
 
         try {