[AGP 9] Update flutter/flutter to AGP 9

[jesswrd]

Updating flutter apps on android in flutter/flutter to AGP 9. Want to ensure the nothing breaks against the new major release AGP 9.

Used this command:

find .  -type d \( -name "engine" -o -name "build" -o -name ".symlinks" \) -prune -o -type d -name "android" -print | sed 's/^/- [ ] /'

checklist of all flutter apps on android:

• [x] ./examples/hello_world/android
• [x] ./examples/layers/android
• [x] ./examples/platform_view/android
• [x] ./examples/flutter_view/android
• [x] ./examples/platform_channel/android
• [x] ./examples/image_list/android
• [x] ./packages/integration_test/example/android
• [ ] ./packages/integration_test/android
• [ ] ./dev/integration_tests/external_textures/android
• [x] ./dev/integration_tests/spell_check/android
• [x] ./dev/integration_tests/ui/android
• [ ] ./dev/integration_tests/deferred_components_test/android
• [x] ./dev/integration_tests/android_views/android
• [x] ./dev/integration_tests/release_smoke_test/android
• [x] ./dev/integration_tests/flavors/android
• [x] ./dev/integration_tests/display_cutout_rotation/android
• [ ] ./dev/integration_tests/android_engine_test/android
• [x] ./dev/integration_tests/android_semantics_testing/android
• [x] ./dev/integration_tests/flutter_gallery/android
• [x] ./dev/integration_tests/android_verified_input/android
• [x] ./dev/integration_tests/platform_interaction/android
• [x] ./dev/integration_tests/channels/android
• [x] ./dev/manual_tests/android
• [ ] ./dev/tracing_tests/android
• [ ] ./dev/benchmarks/multiple_flutters/android
• [x] ./dev/benchmarks/complex_layout/android
• [x] ./dev/benchmarks/macrobenchmarks/android
• [x] ./dev/benchmarks/test_apps/stocks/android
• [x] ./dev/benchmarks/platform_views_layout_hybrid_composition/android
• [x] ./dev/benchmarks/platform_views_layout/android
• [ ] ./dev/benchmarks/microbenchmarks/android
• [ ] ./dev/benchmarks/platform_channels_benchmarks/android
• [x] ./dev/a11y_assessments/android