[pm] use list caches instead of real lists when snapshotting

The actual lists/maps can be changed when snapshotting, causing system
server crashes.

BUG: 255912832
Test: builds
Merged-In: Ia10b4bd47fb3c1d3de577bc4b1a4a70d0d5adc9f
Change-Id: Ia10b4bd47fb3c1d3de577bc4b1a4a70d0d5adc9f
(cherry picked from commit 5733be54b2d8d21336f2efe71d1cc13778779dd0)
1 file changed