Enable flipper android to use different ports based on prop

Summary:
Part 1 of enabling flipper to run on custom ports: android SDK.
Still to go: iOS SDK and desktop

This should allow you to run mobile apps that use flipper on different ports than the default (8089,8088).

`adb shell`
`su`
`setprop flipper.ports 1111,2222`

From what I can tell, this only works on rooted devices.

Reviewed By: passy

Differential Revision: D13753238

fbshipit-source-id: c5f370c9d8c7382e8c17fb81d4010c642ef7c114

xplat/Flipper/FlipperInitConfig.h

@@ -1,11 +1,9 @@
-/*
- *  Copyright (c) 2018-present, Facebook, Inc.
- *
- *  This source code is licensed under the MIT license found in the LICENSE
- *  file in the root directory of this source tree.
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
  *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
  */
-
 #pragma once
 
 #include <folly/io/async/EventBase.h>
@@ -39,6 +37,9 @@ struct FlipperInitConfig {
   EventBase to be used to maintain the network connection.
   */
   folly::EventBase* connectionWorker;
+
+  int insecurePort = 8089;
+  int securePort = 8088;
 };
 
 } // namespace flipper