Add logging to RowInflaterTask

Note that the overall change that adds a dedicated thread for
notification inflation *is* flagged, but this logging is for code that
*doesn't* use the new thread, so it's *not* flagged.

Bug: 308967184
Flag: NA
Test: manual
Change-Id: Idccbb2ffb3b3228952220c69ef0912a7a8347ebd