build: edify: use set_metadata for backuptool

Also use saner permissions on backuptool.sh

Change-Id: I50742b51867aa358f5924b8dc208833092a35bd9
Wrong product package: Gallery was replaced by Gallery2

Change-Id: Ia34e1fa9bc9ac494fac098eb86a5ddab78b6d149
Merge remote-tracking branch 'PA/kitkat' into kitkat-legacy