Split out connectivity-t-pre-jarjar and tests

The pre-jarjar variant is necessary so that service-t can depend on
hidden symbols in framework-t that reference (for example as parameter)
classes that are jarjared.
Without this, when depending on framework-connectivity-tiramisu.impl,
service-connectivity-t would see post-jarjar symbols that do not match
the classnames it uses in its code.

Also split FrameworksNetTestsLib so that the same jarjar rules can be
applied between the tests and the module, avoiding different errors
between FrameworksNetTests and ConnectivityCoverageTests.

Ignore-AOSP-First: Avoiding conflicts; cherry-pick will follow
Bug: 204830222
Test: m
Change-Id: I3d0c081c4a7422e128beee11c0156f01b0377c96
Merged-In: I3d0c081c4a7422e128beee11c0156f01b0377c96