WifiMigration: Add a settings key to indicate migration is complete

Bug: 151888061
Test: Manual verification (ensured that this method returns null after
first reboot)

Change-Id: Ie8ad397c7b68e35cfa7b696ef22d84f376cf3fe7
1 file changed
tree: a6e0f34f6150a353a423aa861fe52f150768fe4b
  1. framework/
  2. OsuLogin/
  3. OWNERS