Merge "Clear buffer on reconnect & check poll() result" into main am: 188eccc45a

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2869329

Change-Id: Iba16f2189e22bda0ce924d6b1da328971fc64df9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>