Mark Android R (rvc-dev-plus-aosp-without-vendor@6692709) as merged

Bug: 166295507
Merged-In: I670b163eede4bb60c197e2ded9491d45ad4b6541
Change-Id: I17d9409df815d08e2379f77a1088880c5bd3b6a2
tree: 703130dd9b051b0f64dd23f4d9c9e2d2a01e70c0
  1. hikey/
  2. hikey960/
  3. update-prebuilts.sh