Avoid UnsupportedOperationException from getDefaultSmsSubscriptionId()

This is basically reverting to earlier behavior.

Test: basic sanity
Bug: 134375393
Merged-in: I44dc66f9f3d5d4dfcab95220d7a6a6be0ed5a825
Change-Id: I44dc66f9f3d5d4dfcab95220d7a6a6be0ed5a825
(cherry picked from commit 900aad99247f81c8f8c5724108c5c64a6f465caa)
1 file changed