Merge "iorap: Add a DEBUG guide on IORap debugging log." into rvc-qpr-dev am: 4b0ec66e am: 396ef95f am: 2d2d6357

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/13001653

Change-Id: I6ddcdfadbc0797af946feb3b5ac1fb456dc5766d