[automerger] Fix a memory leak in gatekeeper. am: 6a9c4e7968 am: bdc924f31d am: 7535975701 am: e126026c02 am: 4ae4ad8e5b am: b25983460c
am: 20e73e23c4

Change-Id: I026aa5ddb79cd10146924fd6625816782645f660