Removed permission check

Removed permission check for getNetworkCountryIso and made it public.
This API was added since the first version of Android. Removed the
permission check for backward compatibility reason.

Test: Telephony sanity tests
Bug: 149872821
Merged-In: I68833fdf6f078d69bc8c2e5f01cf4e058d6d7093
Change-Id: I68833fdf6f078d69bc8c2e5f01cf4e058d6d7093
(cherry picked from commit 0b9a12c2)