Include LICENSE files, when available, in notices.

As a first step to removing the go/android3p instructions to copy or
to link NOTICE to LICENSE, include LICENSE files in the notices, which
will allow deleting all of the copied/linked NOTICE files.

The change causes a couple minor additions to the system image notice
files.

Test: manually built and compared before and after notices

Change-Id: Id23cae4a8f2d103e1379f4341340fc56c5943dc2