Merge "Sync client visibility if activity is stopped" into sc-dev

        // Reset the last saved PiP snap fraction on app stop.

        mDisplayContent.mPinnedTaskController.onActivityHidden(mActivityComponent);

        mDisplayContent.mUnknownAppVisibilityController.appRemovedOrHidden(this);

        if (isClientVisible()) {

            // Though this is usually unlikely to happen, still make sure the client is invisible.

            setClientVisible(false);

        }

        destroySurfaces();

        // Remove any starting window that was added for this app if they are still around.

        removeStartingWindow();