[automerger skipped] [RESTRICT AUTOMERGE] Fix UAF in clearkey service's MemoryFileSystem am: 9ba33b3586 -s ours am: 0a2abba43f -s ours am: a4e3bea9e4 am: 0245e885d3 am: ea7e6b49c9 -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/13711823

Change-Id: Ifb018971f35898215072af617670adacb36b6ad0