Revert "Revert "Move runtime/ to ClassAccessor""

Fixed misplaced UnhideAccessFlags to be outside of a conditional
that the code item is null / not deduped. This fixes an issue
where these methods would not have had their access flags restored.

Bug: 77709234
Bug: 79758018
Bug: 91962648

This reverts commit cc7e20f9.

Test: test-art-host
Test: atest FrameworksUiServicesTests
Test: atest CtsInlineMockingTestCases

Change-Id: I7e5712cdcccef81e19ce81d26743c517b0b8a67d