Add a settings key to expose the device's repair mode state am: 0e1d0ecf

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2781891



Change-Id: I73b5d699f1b741acf84d00318513c70d9835c58f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>