Migrate PackageSetting usages to PackageStateInternal

Moves to a read-only interface inside Computer and all of its
dependencies. This is the next step towards true data model
immutability and mutation time snapshots.

Bug: 202291449

Test: atest PackageManagerServiceUnitTests \
        PackageManagerSettingsTests \
        PackageUserStateTest \
        PackageParserTest \
        PackageManagerTest \
        ScanTests \
        PackageInfoUserFieldsTest \
        DexoptUtilsTest \
        PackageManagerComponentLabelIconOverrideTest

Change-Id: If5afb44e20b50a15b2b99057b0797c9b88e6e60b