Fix OTA info persistence logic

Code to persist OTA info was accidentally removed by a previous CL.
Add it back.

Bug: 73505100
Test: gts-tradefed run gts-dev --module GtsGmscoreHostTestCases --test com.google.android.gts.devicepolicy.DeviceOwnerTest#testPendingSystemUpdate
Change-Id: I9eba522641fd8f95cd6af32431498c2c8ac5ff0e
1 file changed