Correctly translate Cellular Device properties to ONC

This fixes how we translate the Device properties to ONC instead of
just copying the Shill properties.

BUG=279351

Review URL: https://codereview.chromium.org/402953004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285642 0039d316-1c4b-4281-b951-d872f2087c98
8 files changed