Merge "[SystemUI] 1.Remove the unnecessary log 2. update signal icon in bg thread" into sc-qpr1-dev am: c3af8564f9 am: 87af32b289 am: 6eae8f270f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16033980

Change-Id: I3f64e9c312abfc7475140dfbf7a897708f165219