Merge "Limit the visibility of libbinder_rpc_unstable" am: e813ec1500

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2442770

Change-Id: I6d3878721b2458c9300227be23257576361d4559
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>