Merge "Only register stationary detector while idle" into sc-qpr1-dev am:...

Merge "Only register stationary detector while idle" into sc-qpr1-dev am: 65f1d1a5 am: 307c5490 am: d806a4dd

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15639364

Change-Id: I58b4cf17f4f95af34c7389c28a0f954cb5a7de79