[plugins] investigate is setMethodCallHandler:nil required to release the plugin #111206
Description
From the documentation:
/**
* Registers a handler for method calls from the Flutter side.
*
* Replaces any existing handler. Use a `nil` handler for unregistering the
* existing handler.
*
* @param handler The method call handler.
*/
- (void)setMethodCallHandler:(FlutterMethodCallHandler _Nullable)handler;
We need to investigate if resetting the handler is required to release the plugin. If that's the case, we may have memory issue for all our 1P plugins, since they never unregister the handler.