Merge "add source.properties file to the offline docs build which is required to get this in the SDK Manager" into nyc-dev am: 6d0e0bdcd5 am: 9f05056ccd am: c8dd22bcdf am: 237bf1f923
am: 6ee18e6219

Change-Id: I6b9b73e97d312df368bdff954b29cdad92d4de34