Add serialization tests for libaudioclient am: d980f658 am: 515d7e74

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/2190001



Change-Id: I4dd6e9949a7ba656e8aba9e371e4f65c8b67e66c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>