Load all groups data from editor

GroupMembershipView needs all group data to determine which group
is favorites/default, so when we load from the editor use the old
selection string.

Test:
Followed steps in bug and made sure the contact wasn't booted from
the My Contacts list, and the selected labels were updated properly.
Also tested adding multiple new labels and saving those.

Bug: 31750797
Change-Id: I84b1be6c17f2acf46efc202fb81a2c180cc2bcae