Add prebuilt protobuf 3.9.1 to vendor partition. am: 112ddf05d3 am: b373ca513b

Original change: https://android-review.googlesource.com/c/device/google/bramble/+/2297097

Change-Id: Id23757046c201e778c1b14fde09136ed24c40a22
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>