Move the QrCodeGenerator from Settings to SettingsLib for Wifi and BT

Bug: 214338905
Test: Manual test
Test: make RunSettingsRoboTests ROBOTEST_FILTER=QrCameraTest
Change-Id: I1ca3e9e0b2cdc9fd3f32da8c5329c0e887ee3427
Merged-In: I1ca3e9e0b2cdc9fd3f32da8c5329c0e887ee3427
3 files changed