Fix memory leak in SystemUI

It was introduced in:
https://github.com/TeamHorizon/platform_frameworks_base/commit/dc3bbadd709127aa38a12c60f5e7753ac8685ca1

Change-Id: Id233476409e93aa25f93d3ee9c8e7bfb9a57362b
Signed-off-by: arham jamal <arhamjamal@gmail.com>