Add OWNERS files for app hibernation

Add OWNERS in services/core/java/com/android/server/apphibernation for
system service code and core/java/android/apphibernation/OWNERS for
client-facing code.

Bug: 175829330
Test: builds
Change-Id: I76d95309b641d9e75e68a50c6563df9f95b9c142
2 files changed