* Added notificationListner sample code

* Fixed spacing

* fixed spacing

* Moved the variables into the Build method

* fixed typos

* Update packages/flutter/lib/src/widgets/notification_listener.dart
Co-authored-by: John Ryan <ryjohn@google.com>

* Update packages/flutter/lib/src/widgets/notification_listener.dart
Co-authored-by: John Ryan <ryjohn@google.com>

* Update packages/flutter/lib/src/widgets/notification_listener.dart
Co-authored-by: John Ryan <ryjohn@google.com>

* Update packages/flutter/lib/src/widgets/notification_listener.dart
Co-authored-by: John Ryan <ryjohn@google.com>

* Update packages/flutter/lib/src/widgets/notification_listener.dart
Co-authored-by: John Ryan <ryjohn@google.com>

* Update packages/flutter/lib/src/widgets/notification_listener.dart
Co-authored-by: John Ryan <ryjohn@google.com>

* Update packages/flutter/lib/src/widgets/notification_listener.dart
Co-authored-by: John Ryan <ryjohn@google.com>

* [integration_test] Reland add a `run` method for proper reporting of test results

* Changes to path resolving from previous PR

This reverts commit 2a5aa294.

Additionally, fix a few NNBD issues.

Fixes https://github.com/flutter/flutter/issues/70408

This reverts commit 8749d955.

* Disable failing test due to SDK issue

* Disable failing debugger and hot reload windows tests

In principle this is backwards compatible; I just merged all the classes into one and deprecated everything that became redundant as a result.

Address comment in https://github.com/flutter/flutter/pull/66386/files#r522671103

* 03ff8a409 TBR: remove the extra values which was overshadowing the test result (flutter/engine#22483)

* e9b6a428f Roll Skia from a06b63c56ecd to 8ead30d51c86 (1 revision) (flutter/engine#22487)

* ee700513e Roll Fuchsia Linux SDK from fULjPqtx9... to B4PaMsNWM... (flutter/engine#22490)

* 4cbb684ef Roll Dart SDK from 3e502e0c7e04 to 41893ff76b0f (1 revision) (flutter/engine#22491)

* 38b6c22d5 PlatformViewIOS CreateExternalViewEmbedder refactor (flutter/engine#22353)

* bbcf19ad1 Roll Skia from 8ead30d51c86 to 011218edb590 (4 revisions) (flutter/engine#22493)

[flutter_tools] use initially parsed package config for language version, sound mode determination (#70323)

Revert "[integration_test] Add a `run` method for proper reporting of test results (#70075)" (#70466)

This reverts commit af5eb3b9.

Change the semantics of Actions.invoke so that if the action it finds is disabled, then it keeps looking for an ancestor Actions widgets that has a matching intent where the action is not disabled.

[flutter_tools] remove branch migration and standardize constructor style for version interface (#70058)

Migrate flutter_localizations to null safety.

This reverts commit a0ec4d67.

Unit tests that cover their translations are also added.