(Attempt to reland #85993)

This reverts commit 2175e64e.

Migrate core devicelab framework to null safety.

This reverts commit 05d55157.

This reverts commit ef2879a4.

Removes one-off handling for defines test and forces it to run through the DriverTest interface

Split the integration_ui target into individual driver tests. Remove disabled screenshot tests

Remove devicelab specific code for shutting down gradle daemon, add --android-gradle-daemon option to build/run/drive`. Avoids need for un-tested devicelab specific handler. There are also some feature requests for this, so 2 birds one stone.

Example:

flutter build apk --no-android-gradle-daemon will pass --no-daemon on to gradle

This reverts commit ddab72e7.

Remove devicelab specific code for shutting down gradle daemon, add --android-gradle-daemon option to build/run/drive`. Avoids need for un-tested devicelab specific handler. There are also some feature requests for this, so 2 birds one stone.

Example:

flutter build apk --no-android-gradle-daemon will pass --no-daemon on to gradle

Currently these tests are taking CI time without providing any value, because there is no verification that network connectivity is avoided. This is better covered by a unit test that verifies that --offline is passed to pub.

* enable macOS desktop

* enable all configs on CI

* Update track_widget_creation_enabled_task.dart

* Update framework.dart

* remove FLUTTER_WEB

* remove config environment variables

* configure in correct spot

This reverts commit 357fd2db.

This reverts commit e03f4391.

This reverts commit adec6977.