Bug: 122855168 Test: rebuild Change-Id: I962d9a71179f86b7cae9dc5e9a00e0aa1557dc76
1.Add a button to launch QR code scanner when add a network. 2.Scan button added in AddNetworkFragment / WifiDialog / WifiSettings. Bug: 120630683 Test: make RunSettingsRoboTests Change-Id: I340bfa2247e092f586dd90dfea37c355e681ffee