mixed builds: add cc_test bazel handler, and add adbd_test to staging allowlist.

This will allow the test_suites_{arm64, x86_64} CI targets on
git_master-bazel to build adbd_test with bazel in `m`.

This is currently implemented similar to the cc_binary handler to
hydrate the output path field.

The tradefed config is still currently handled by Soong in
testBinary#install, which is called from both ProcessBazelQueryResponse
and GenerateAndroidBuildActions. We'll move the tradefed config path to
a mixed builds handler when it's ready on the cc_test bazel rule side.

Tested with `atest` with cuttlefish. Since `atest` doesn't have a way to pass
--bazel-mode-staging to its internal call to Soong, so I manually tested
this by adding adbt_test to the prod allowlist, and confirmed that the
installed adbd_test is the same binary as the one in bazel-out.

Test: $ showcommands adbd_test | grep bazel-out | tail -n1

```
/bin/bash -c "rm -f
out/target/product/vsoc_x86_64/data/nativetest64/adbd_test/adbd_test &&
cp -f -d
out/bazel/output/execroot/__main__/bazel-out/android_x86_64_silvermont-opt-ST-59d4124ca041/bin/packages/modules/adb/adbd_test
out/target/product/vsoc_x86_64/data/nativetest64/adbd_test/adbd_test"
```

Test: Add adbd_test to prod allowlist and run 'lunch aosp_cf_x86_64_phone-userdebug; atest adbd_test', all tests pass.
Bug: 258426425
Bug: 261692372
Change-Id: I6be329f39d607af8daa1dc772b23e8dd0247418c