Merge "libbinder: allow multiple outgoing threads for single-threaded" am: 1c63a158aa am: 6daa07a862

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2167825

Change-Id: Id16cb0242cd8143d8ee2ec10f9e9fec795afe6b0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>