Add a factoryReset method to IIpMemoryStore, and freeze api.

Currently unimplemented. Implementation will be in a future CL.

Test: m
Bug: 128499160
Change-Id: Ia11ecd33f528d01667b1baeb8671b7213a31eef5
Merged-In: Ia11ecd33f528d01667b1baeb8671b7213a31eef5
(cherry picked from commit 10ddc681)