Add `OWNERS` file to `device/generic/art`. am: fae1a45444

Original change: https://android-review.googlesource.com/c/device/generic/art/+/3206470

Change-Id: Ibfe19adbcde10efdda9bf2ccd457c8fa82243c56
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>