Merge "New hidden DPM methods: getLogoutUserId() and clearLogoutUser()." into sc-v2-dev am: b3137b3b86

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16245093

Change-Id: I73aded8d5b2f1bd38adba570d2eab4c6d84cdea8