[automerge] Revert "Revert "Skip restore of read-only directories"" 2p: 9e7c309cf2 am: 95b37f46e6

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17034290

Change-Id: I0d1d137ebf3facfec8759e4a05180cb2afee25ac