Merge "MediaCas: Release cas resource only when all sessions are closed" into main am: e9e7e78f65

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/3016424

Change-Id: Id8432aa07a3f72c23c11b0e90d07c022c5f65523
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>