base: added national roaming for 3AT on t-mobile austria

Users of 3AT (MCC 232 MNC 11) can roam on t-mobile (MNC 03)

Change-Id: I5bb6f73c43b7f57c59deda5dc4e70d98c90fdbb9
(cherry picked from commit 3d597b6e9ff51c3fceba9fe623f97cd0a2eaa395)