Merge "Initialize ContentObserver in startObserving()." into tm-qpr-dev am: af0795a722 am: e9c793f8c4

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20111661

Change-Id: Ie1890672bf962e49bc7cf1630012afb6d0a28f1b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>