Merge changes I0af0ad24,I942c92fd,Ibc8920dd,Icfce9c1e,I1c6cc616, ...

* changes:
  DO NOT MERGE: Split 'generating' and 'pulling' in 2 messages.
  DO NOT MERGE: Ignore bugreportz output when it's not supported.
  DO NOT MERGE: Deprecated 'adb bugreport' with flat files.
  DO NOT MERGE: Minor improvements on bugreport generation.
  DO NOT MERGE: Removed extra 'pulling file' message.
  DO NOT MERGE: Show bugreport progress.
  DO NOT MERGE: Refactored functions that copy sdout and stderr to strings to use a callback.
  DO NOT MERGE: Split bugreport() into its own file and added unit tests.
  DO NOT MERGE: use 'cmd' command for install-multiple
  DO NOT MERGE: Ensure the target sees a proper EOD marker during restore