Add bufferpool AIDL definitions am: 1468ddfbf3 am: 45c5a7bf27

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2283539

Change-Id: Ie9385fd2817226de705900e70e24454b4e5bcf32
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>