Do not load app image for class collisions

Even for special shared libraries that are compiled with
'--class-loader-context=&', we must reject the app image
if there are duplicate classes.

In the case where "&" is not specified, avoid the collision check.
This is safe since the class loader context check was actually run.

Test: 172-app-image-twice
Bug: 77342775
Bug: 79200502

Change-Id: Idc2d59166680948d4d34d0f224491f77ecad2974