Yielding cell wins to exiting wifi (whether good or bad).
It loses to bad wifi that's not exiting.
In R, yielding to bad wifi only affects wifis that are
unvalidated, but a wifi that is exiting should still be
dropped in favor of a cell that yields to bad wifi.
I had misunderstood the policy and implemented it wrong.
Now it's implemented right, and has careful tests.
Test: new tests for this
Bug: 186458024
Change-Id: Ib8637100d491e72a2edb837584ce55b7dda58524
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
