Check if Packages.bz2 file exists in Ubuntu debian-installer repo
Otherwise use Packages file
Get back indices for debian-installer repos

Change-Id: Ic73da1f32eff9af9ddb4a33a7c68771d4c198d08
Closes-bug: #1307949
Merge "Check if Packages.bz2 file exists in Ubuntu debian-installer repo Otherwise use Packages file Get back indices for debian-installer repos"