Ensure that LockSettingsService waits for gatekeeperd to be ready am: e59460902b

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2775385

Change-Id: I8c5a5d8e6dd959a54c36d2b71b51b768fe44fc32
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>