Added getActiveSubInfoCount

Added getActiveSubInfoCount and migrated more modules
to use SubscrtipionManagerService.

Test: atest FrameworksTelephonyTests
Bug: 239607619
Merged-In: Ie5c929fa7efe24d85385b6939a204d90d76d6b34
Change-Id: Ie5c929fa7efe24d85385b6939a204d90d76d6b34
1 file changed