Merge "AudioDeviceInventory: fix purge of device role cache." into udc-dev am: cd5243dc

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23712844



Change-Id: I848a46044854cb8183756d273852974d928c8823
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>