Roaming notification for ONLY_ALLOWED_SINGLE_NETWORK case

If ONLY_ALLOWED_SINGLE_NETWORK disallow reason exists, roaming
notifications will be updated once more after the Internet is
completely disconnected.
If carrier uses a single data network, wait until your Internet
connection is completely disconnected and update notifications
once again to check if the reason for disallowance has been
disappeared.

Bug: 249908996
Test: manual test for single data network
Change-Id: I4a2d1a42d7426096fa5f4fae42d74129df177373
1 file changed