Merge tag 'android-8.1.0_r4' into HEAD

Android 8.1.0 Release 4 (OPM1.171019.013)

# gpg: Signature made Tue Jan  2 18:41:18 2018 CST
# gpg:                using DSA key 4340D13570EF945E83810964E8AD3F819AB10E78
# gpg: Good signature from "The Android Open Source Project <initial-contribution@android.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 4340 D135 70EF 945E 8381  0964 E8AD 3F81 9AB1 0E78