Fix where country change results in emergency number update failure.

Clearing the current database version on emergency country ISO change
ensures that when the emergency numbers are updated from the database that
we will refresh the most recent values.

Bug: 173456532
Test: unit test; phone screen verified
(cherry picked from commit a8d6cbf4)
Change-Id: I46fec3d522468d8dd1d627295b740c724e508b0c
Merged-In: I377fa53111dfcffd92d050b652b3ed29c8354492