Revert "Make MmsManager public"

This reverts commit 2137c9bd3905def08015d83cf15dda1bc3d97679.

Reason for revert: Reverted internally

Change-Id: I6bed6facba681fa4abee739be50e21700b37c84a
Merged-In: I5952168aba996a10554406a9f1675ac3b04fa41f
4 files changed