[automerger skipped] Fix leakage of DisplayContent referenced from TransitionController am: 6c04f9b6 -s ours am: e993518a -s ours am: 4a65ab81 -s ours am: 1144176e -s ours am: dc05b1b8 -s ours

am skip reason: Merged-In I44e2a794981fc114ada0ce98cd2471adf623d856 with SHA-1 c3eaf662 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17061629

Change-Id: I92b3111996b2e13f67c72c0460c539a57959ab4c