Use public API to determine apk-in-apex

To determine if the given packageName is an apk-in-apex, currently we
are using getActiveApexPackageNameContainingPackage which is an hidden
API. We have a better Public api getApexPackageName for the same.

Bug: 289203818
Test: TH
Flag: android.crashrecovery.flags.refactor_crashrecovery
Change-Id: I1451502ab8bdb2df9171aae5dd6b52636ab2a4aa