Remove iOS platform check for running devtools

Summary:
Currently, DevTools only work under ios (although this is undocumented!), because the JavaScriptEngine initialization process skips setupDevTools() on android.

DevTools work fine with Android, as tested on 0.26, 0.27, and 0.28 using Nuclide's inspector.

For reference, [the relevant issue on react-devtools](https://github.com/facebook/react-devtools/issues/229).
Closes https://github.com/facebook/react-native/pull/8095

Reviewed By: javache

Differential Revision: D3443980

Pulled By: andreicoman11

fbshipit-source-id: 3d7b2e83cf4158a1228d2e21510509ab63411a5d

ReactAndroid/src/androidTest/java/com/facebook/react/testing/FakeWebSocketModule.java

@@ -0,0 +1,60 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react.testing;
+
+import javax.annotation.Nullable;
+
+import com.facebook.react.bridge.Arguments;
+import com.facebook.react.bridge.BaseJavaModule;
+import com.facebook.react.bridge.ReactMethod;
+import com.facebook.react.bridge.ReadableArray;
+import com.facebook.react.bridge.ReadableMap;
+import com.facebook.react.bridge.WritableMap;
+
+/**
+ * Dummy implementation of storage module, used for testing
+ */
+public final class FakeWebSocketModule extends BaseJavaModule {
+
+  private static WritableMap errorMessage;
+  static {
+    errorMessage = Arguments.createMap();
+    errorMessage.putString("message", "Fake Fake Web Socke tModule");
+  }
+
+  @Override
+  public String getName() {
+    return "WebSocketModule";
+  }
+
+  @Override
+  public boolean canOverrideExistingModule() {
+    return true;
+  }
+
+  @ReactMethod
+  public void connect(
+    final String url,
+    @Nullable final ReadableArray protocols,
+    @Nullable final ReadableMap headers,
+    final int id) {
+  }
+
+  @ReactMethod
+  public void close(int code, String reason, int id) {
+  }
+
+  @ReactMethod
+  public void send(String message, int id) {
+  }
+
+  @ReactMethod
+  public void sendBinary(String base64String, int id) {
+  }
+}