Merge "binder_process.h: clarify thread start behavior" into main am: 0ce759a077

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/3228527

Change-Id: I9cd928cacb21150d1b3c37293f5de40add826acf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>