Re-lands https://github.com/flutter/flutter/pull/137191.

The fix for the issue causing that PR to be reverted was tested in this PR but ultimately landed separately in https://github.com/flutter/flutter/pull/138093.

Reverts flutter/flutter#137191
Initiated by: camsim99
This change reverts the following previous change:
Original Description:
Adds support for Android 34 in the following ways:

- Bumps integration tests compile SDK versions 33 --> 34
- Bumps template compile SDK version 33 --> 34
- Also changes deprecated `compileSdkVersion` to `compileSdk`

Part of https://github.com/flutter/flutter/issues/134220

Adds support for Android 34 in the following ways:

- Bumps integration tests compile SDK versions 33 --> 34
- Bumps template compile SDK version 33 --> 34
- Also changes deprecated `compileSdkVersion` to `compileSdk`

Part of https://github.com/flutter/flutter/issues/134220

Partially fixes/related to: https://github.com/flutter/flutter/issues/131425

Bumps integration tests (that are not run manually only) using `compileSdkVersion` 31 to 33.

See https://docs.flutter.dev/reference/supported-platforms

I don't expect this to break anything, but if it does we can revert and figure out what else needs to happen first.

Without this change, engine changes upstream will get flagged in default flutter created apps.

This reverts commit 9038fac9.

This reverts commit 058dfd49.

This reverts commit 8e73bab9.

This reverts commit 5b3dc525.

Update Android activities because plugin registration is now done by FlutterActivity.configureFlutterEngine (#50841)

* drop unnecessary test deps

* bump to junit 4.13

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

* Test the Android embedding v2

* Update integration tests

* Split into shards