API Council Feedback - Override EmergencyNumberDB File API

Use ParcelFileDescriptor; Introduce Reset API

Test: atest TelephonyHostTest#testEmergencyNumberDb
Bug: 147805285
Change-Id: I7a7733c02874c0f17fef8c91b9e543c8e803f504
Merged-In: I7a7733c02874c0f17fef8c91b9e543c8e803f504
(cherry picked from commit 75c49ab3345c47d18cebc8a1b932d1ef3829f37d)
4 files changed