libhwbinder: support '0' fd for binder am: d2c941f559 am: fd57a9438f

Original change: https://android-review.googlesource.com/c/platform/system/libhwbinder/+/1557025

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I15c28d5b8c6c82870c51b5fad7876d89311c4718