Add InstantAppDomainsPreference for Spa

To try:
1. adb shell am start -n com.android.settings/.spa.SpaActivity
2. Go to Apps -> All apps -> [One Instant App] -> Supported links

Bug: 236346018
Test: Unit test
Test: Manually with Settings App
Change-Id: I344ddb9c2f3dbc47d38554bf45f04ca7c26c0e5f