The build file currently holds a single build rule in test/. Move it to
the existing build file in tests/common/Android.bp.
Test: m
Bug: 186628461
Change-Id: I3948c9b46e2647f945a22f16aad493e94fe50b4d
Move the tests together with packages/Connectivity code, so both can be
moved to packages/modules/Connectivity together.
Also reorganize unit tests in a unit/ directory, as other tests
(integration/, common/ etc.) have been added in tests/net since they
were created. This makes the directory structure consistent.
Test: atest FrameworksNetTests
Bug: 187814163
Ignore-AOSP-First: needs per-branch move for merge conflicts
Change-Id: I254ffd1c08ec058d594b4ea55cbae5505f8497cc
