Skip showing Call Forwarding fail-to-disable dialog

AT&T México's network returns active status even if disable
callforward succeeded, then the un-wanted error dialog will
be shown. So, skip showing the error dialog.

Test: manual - checked the call forwarding fail dialog was not shown
Bug: 35790386
Change-Id: Ib8021d308781d8c941c10d231d5bad8896bdb370
1 file changed