Break shared library adds into populate and modify

This change breaks current modification of shared lib state in the
system into object creation and a commit step so that multiple packages
may be interrogated before committing anything to the system.

Change-Id: I466d588be3e9690cffc8a04e025145d747fcbb2f
Bug: 109941548
Test: atest StaticSharedLibsHostTests
2 files changed