Allow carrier apps for non-default subs to access voicemail.

The previous implementation only permitted carrier apps on the default
subscription. However, even if a carrier's subscription is not
default, it may still legitimately need to access the voicemail
provider to insert new messages, since these subs can still be used
for voice calls and since voicemails can come in asynchronously.

Test: Build, TreeHugger
Fixes: 133265596
Change-Id: Ifc3e587d07fa926246456546c17742ad8fd6a34e
1 file changed