resourcemanager: refactor death notification am: f9137e41

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/23783756



Change-Id: I7524a40b9299687ce5f33f5ee9e83e40aa9c11fc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>