update addon layouts

packages/flutter_mozilla_components/android/src/main/res/values/colors.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<resources xmlns:tools="http://schemas.android.com/tools">
+    <color name="icons">#ffffffff</color>
+</resources>