Merge "Attempt to clear memory after keyguard PIN entry" into sc-dev am: f16b3f76 am: abd75290 am: 60f66941

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15502355

Change-Id: I021193c75fc739c8a380dfb951d60c1b2692886d