Merge "Fix NPE during restartBleScan() when scanner is null" into sc-v2-dev am: e5e42892c5 am: 5a093c5a74

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16166922

Change-Id: I22dbbdf48a0e2f74a44c3d647c2cd31b0fcabd0d