@@ -0,0 +1,619 @@
+package com.zulip.android.util;%0A%0Aimport android.app.Activity;%0Aimport android.content.Context;%0A%0A/**%0A * Default Activity transition animation.%0A */%0A%0Apublic class ActivityTransitionAnim %7B%0A    /**%0A     * All usages must pass an activity context to execute a transition.%0A     *%0A     * @param activityContext %7B@link Context%7D%0A     */%0A    public static void transition(Context activityContext) %7B%0A        // avoid invalid class cast exception%0A        if (activityContext instanceof Activity) %7B%0A            ((Activity) activityContext).overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out);%0A        %7D%0A    %7D%0A%7D%0A

Add default activity transition class ActivityTransitionAnim.