Define permission for installer API v2

The package installer v2 APIs were marked as @SystemApi merely as
a convenience for development. These APIs may change in the next
version of Android and their usage must be strictly controlled.

Bug: 151716357
Test: Manual. Use old Shell and see that incremental installation fails with a SecurityException
Test: Manual. Request INSTALLER_V2 permission for shell and see that incremental installation succeeds
Change-Id: I9612dc145eadda20083bcc43e7a35ef3cd90aa40