Merge "Do some additional cleanup when switching handlers" into sc-dev

    /**

     * Cancels any running animation so that the active target can be overriden by a new swipe

     * handle (in case of quick switch).

     * handler (in case of quick switch).

     */

    private void cancelCurrentAnimation() {

        mCanceled = true;

        mCurrentShift.cancelAnimation();

        // Cleanup when switching handlers

        mInputConsumerProxy.unregisterCallback();

        mActivityInitListener.unregister();

        ActivityManagerWrapper.getInstance().unregisterTaskStackListener(mActivityRestartListener);

        mTaskSnapshot = null;

    }

    private void invalidateHandler() {