Merge "profcollect: Register observers in a background thread" am: 75b0b6eefd am: 565e165188 am: 97cd22b11f

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2017976

Change-Id: I62339112f1a5d3e863f532dd3d68215b6a9246cc