releasetools: Add a verbose parameter to common.Run().

Caller can optionally specify the verbose flag which overrides
OPTIONS.verbose. The command line won't be outputed with verbose=False.
This is useful for cases that a) those command lines are less useful
(but will spam the output otherwise); b) sensitive info is part of the
invocation.

'verbose=False' will be consumed by common.Run() only, instead of being
passed to subprocess.Popen().

Test: ota_from_target_files.py on a block based OTA.
Change-Id: I7d5b4094d756a60f84f89c6a965e7ccc68e435f8