Telephony: Consider dataRegState to determine SPN display

There may be situations where voice service state is OOS and data
service state is IN_SERVICE. In such cases, both regStates need to be
considered to determine what to show in UI for SPN.

Change-Id: Iab17ed07611b6fd95d6bc6ee3e2e095f6700e3ba
CRs-Fixed: 532471
(cherry picked from commit 2e82847bccabaea72796c1b147ca1ace92567b41)
(cherry picked from commit a8a96a1c846ad2a36b861c6d3c526a3f7edf130d)
(cherry picked from commit c13654c1db55d5963e8a42d6ba23134661258605)