Reverts flutter/flutter#140115

Initiated by: bartekpacia

Reason for reverting: broke the tree

- [`Linux firebase_abstract_method_smoke_test`](https://ci.chromium.org/ui/p/flutter/builders/prod/Linux%20firebase_abstract_method_smoke_test/15844/overview)
- [`Linux_android android_view_scroll_perf__timeline_summary`](https://ci.chromium.org/ui/p/flutter/builders/prod/Linux_android%20android_view_scroll_perf__timeline_summary/13453/overview)
- [`Linux_android platform_views

Original PR Author: bartekpacia

Reviewed By: {gmackall}

This change reverts the following previous change:
Original Description:
This PR updates almost* all Gradle buildscripts in the Flutter repo the `example` and `dev` (in particular, in `dev/integration_tests` and in `dev/benchmarks`) directories to apply Flutter's Gradle plugins using the declarative `plugins {}` block.

*almost, because:
- add-to-app (aka hybrid) apps are not migrated (related https://github.com/flutter/flutter/issues/138756)
- apps that purposefully use build files to ensure backward compatibility (e.g. [`gradle_deprecated_settings`](https://github.com/flutter/flutter/tree/3.16.0/dev/integration_tests/gradle_deprecated_settings))

This PR updates almost* all Gradle buildscripts in the Flutter repo the `example` and `dev` (in particular, in `dev/integration_tests` and in `dev/benchmarks`) directories to apply Flutter's Gradle plugins using the declarative `plugins {}` block.

*almost, because:
- add-to-app (aka hybrid) apps are not migrated (related https://github.com/flutter/flutter/issues/138756)
- apps that purposefully use build files to ensure backward compatibility (e.g. [`gradle_deprecated_settings`](https://github.com/flutter/flutter/tree/3.16.0/dev/integration_tests/gradle_deprecated_settings))

Reland "Upgrade Gradle and AGP versions to 7.5/7.2 and migrate benchmarks+examples" #108472 (#108510)

Revert "Reland "Upgrade Gradle and AGP versions to 7.5/7.2 and migrate benchmarks+examples" #108355 (#108472)" (#108488)

This reverts commit 1f8c490c.

Reland "Upgrade Gradle and AGP versions to 7.5/7.2 and migrate benchmarks+examples" #108355 (#108472)

Revert "Reland "Upgrade Gradle and AGP versions to 7.5/7.2 and migrate benchmarks+examples" (#108355)" (#108407)

This reverts commit c4b3625d.

This reverts commit bfe9c598.

This reverts commit 9038fac9.

This reverts commit 058dfd49.

This reverts commit 31e33647.

This change updates the platform runners in the benchmarks subdir.

I've attempted to replace the entire group with new code as if the project were recreated with flutter create so that they don't become a Frankenstein of minor changes to make it work again, but just plain old generated code that can be replaced and updated in place.

* Revert "Mark last failing test after gradle update as flaky. (#91423)"

This reverts commit 46a52d03.

* Revert "fix android template for Gradle 7 (#91411)"

This reverts commit 51d06d53.

* Revert "Add explicit version for mac and windows openjdk. (#91408)"

This reverts commit bf429f27.

* Revert "Update the openjdk version used by linux android tests. (#91405)"

This reverts commit 2144ab8b.

* Revert "Migrate to Gradle 7.0.2 / AGP 7.0.1 (#90642)"

This reverts commit b6459f9b.