PatchPanel: fix deadlock when releasing a patch am: 34e55a460c am: 0941f6e1bc am: 28835a324a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/22813518

Change-Id: I52a7c8356494a097470b085bdfeb8add2bfb84a4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>