Simplify per-target-SDK LinkProperties tests.

Currently these tests run as hostside tests and require a lot of
boilerplate, including their own CtsHostsideNetworkTestsApp3
build target.

Move the coverage to LinkPropertiesTest using the new-ish
@CtsNetTestCasesMaxTargetSdk31 annotation, and remove the
hostside tests.

The only test that is not being moved is one that checks the
behaviour of disabling the compat change on T. This test is not
very useful because it can only run on userdebug builds and not
on production builds, because CtsHostsideNetworkTestsApp3 targets
SDK 33. We do have test coverage for disabling the compat change
on an app targeting SDK 31, where it is allowed.

Fix: 236087258
Test: atest CtsNetTestCasesMaxTargetSdk31
Test: atest CtsNetTestCasesLatestSdk:android.net.LinkPropertiesTest
Change-Id: I6d4b1ba40f6cb63b30a600c227e9628858c03d73