Merge "Allow doze dream package to start a DreamActivity" into rvc-dev am: 45387676fc am: 1471729544 am: 87d2078b50

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/12066923

Change-Id: Iee9e653bab9a774fe344efac3d25cd972504ecf3