Add proguard rule for GeckoView
Add proguard rule for GeckoView

jonalmeida/focus-android,ekager/focus-android,jonalmeida/focus-android,jonalmeida/focus-android,jonalmeida/focus-android,jonalmeida/focus-android,mozilla-mobile/focus-android,ekager/focus-android,mozilla-mobile/focus-android,ekager/focus-android,mozilla-mobile/focus-android,mozilla-mobile/focus-android,ekager/focus-android,mozilla-mobile/focus-android,mozilla-mobile/focus-android,ekager/focus-android,jonalmeida/focus-android,ekager/focus-android