Use cached getPackageInfo for target overlayable

App filtering is currently non-revokable, so skipping the cache isn't
necessary. If the cache returns any value, that means it's valid until
a clear of the cache, so it's callable from this location.

Bug: 152326342

Test: atest OverlayHostTest
Test: atest OverlayActorEnforcerTests

Change-Id: Iead0bee9dd51868920fed4afc68b4dcbc269f62c