[ci] Enable Android emulator-based tests (#4494)

Adds emulators to the Android platform test tasks, and enable both native integration tests and `flutter test` Dart integration tests. This finally gives us presubmit coverage of Android integration tests for non-team-member PRs, as well as giving us a path to reducing the dependency on FTL for all of our Android testing.

Currently this uses Android 13 emulators; we could expand this to a set of legacy version emulator tests in the future once this is in place.

Some specific notes:
- Camera and Google Maps tests are currently excluded, so that we can enable everything else while we work on the blockers for those.
- `shared_preferences` was missing its debug entitlement, which prevented the debug service from running, and thus broke `flutter test`; we'd just never noticed because FTL tests don't need that mechanism to work.
- IAP was using `test` instead of `testWidget`, which we only check for in `drive-examples`, so hadn't noticed.

Fixes https://github.com/flutter/flutter/issues/93810

script/configs/exclude_integration_android_emulator.yaml

@@ -0,0 +1,8 @@
+# Hangs due to permission issue, see https://github.com/flutter/flutter/issues/130987
+# TODO(stuartmorgan): Remove once the permission issue is addressed.
+- camera/camera
+- camera_android
+- camera_android_camerax
+# Frequent flaky failures, see https://github.com/flutter/flutter/issues/130986
+# TODO(stuartmorgan): Remove once the flake is fixed.
+- google_maps_flutter_android