Allow a shared library to be positioned after the application on the classpath

This is useful if/when it's desired that an application contains the same
fully qualified class name that's also in the library.

The shared libraries that are treated in this manor are controlled by the resource
com.android.internal.R.config_shared_libraries_loaded_after_app

Bug: 179429740

Test: atest SharedLibraryLoadingTests

Change-Id: Ia37ff9bd545918d1e0f1f38548dcd86f177559d5