surfaceflinger: IBinder leak

TransactionCompletedThread never deleted its Listener sp<IBinder>
tokens from its pending thread which can lead to SurfaceFlinger
crashes. This patch adds the support for removing the sp<IBinder>
tokens when SurfaceFlinger is done with them.

Test: TransactionTest
Bug: 130430082

Change-Id: Icd773fc18f1a0440857bc65111c51c890746a42b