Old Android Stuio versions pior to 2.2.0 didn't come with Java bundled. Make sure flutter doesn't crash when we try to determine the Java version of those old Android Studio installations.

* Update the examples README file

* Addressed comment

This reverts commit 38e4e48d.

* adds highlight + splash color properties to material button

* add states to raised button + flat button

* fixes an issue where the custom highlight would not be properly set

* Add preliminary tests for theme highlight + splash and via theme

* documentation changes. tweaks per code review feedback

* comment out unused variable

* remove unused import

* documentation updates. removed commented code

* Use Java bundled with Android Studio for gradle

* review comments

Go through all packages brought in by pub, and write the name and path of every one that is a flutter plugin into .flutter-plugins.

In android/settings.gradle and ios/Podfile, read in .flutter-plugins, if that file exists. The Android / iOS code from the plugins is automatically added as dependencies of the native code of the app.

* Add start-up test for flutter_view sample

* add reportMetrics flag to startup test

* rewording in manifest.yaml

**THIS IS A BREAKING CHANGE.** See below for migration steps for
existing projects.

Previously, Flutter app code was built as a raw dylib on iOS.  Dynamic
libraries outside of a framework bundle are not supported on iOS, except
for the system Swift libraries provided by Xcode.

See:
https://developer.apple.com/library/content/technotes/tn2435/_index.html#//apple_ref/doc/uid/DTS40017543-CH1-TROUBLESHOOTING_BUNDLE_ERRORS-EMBEDDED__DYLIB_FILES

* Migrates Xcode build from app.dylib to App.framework
* Migrates flutter create template
* Migrates example projects

Migration steps for existing projects
=====================================

The following steps should be taken from the root of your Flutter
project:

1. Edit `ios/.gitignore`: add `/Flutter/App.framework` on a new line.
2. In the Xcode project navigator, remove `app.dylib` from the Flutter
   folder. Delete this file from the `ios/Flutter` directory in your project.
3. Run a build to generate `ios/Flutter/App.framework`. From the command
   line, run `flutter build ios`. If you have not configured app signing
   in Xcode, an alternative method is to open the simulator, then run
   `flutter run -d iP`.
4. In the Xcode project navigator, select the `Runner` project. In the
   project settings that are displayed in the main view, ensure that the
   `Runner` target is selected. You can verify this by exposing the
   sidebar using the [| ] icon in the upper-left corner of the main
   view.
5. Select the *General* tab in the project settings. Under the
   *Embedded Binaries* section, click '+' to add `App.framework`. In the
   sheet that drops down, click the *Add Other...* button. Navigate to
   the `ios/Flutter` directory and select `App.framework`. Click *Open*.
   In the sheet that drops down, select *Create folder references*, then
   click *Finish*.
6. In the project settings, verify that `App.framework` has been added to the
   *Embedded Binaries* and *Linked Frameworks and Libraries* lists.
7. In the Xcode project navigator, drag `App.framework` under the
   Flutter folder.
8. In the Xcode project navigator, select `Flutter` then from the
   *File* menu, select *Add Files to "Runner"...*. Navigate to the
   `ios/Flutter` directory, select `AppFrameworkInfo.plist` and click
   the *Add* button.
9. From the command line, in your project directory, run
   `flutter build clean`, then `flutter run`.

At this point your project should be fully migrated.

* Teach flutter_tools to populate PUB_ENVIRONMENT

Will allow telemetry reporting on pub.dartlang.org once
flutter moves to 1.23.0-dev.10.0

* review changes

* Improvements to CircleAvatar default color (for codelab)

* use a transparent white instead of a solid one

* Fix analyzer errors

* fix tests

* Print error message if a package is skipped during DevFS sync.

* review comments

* more review comments

* fix test

* Remove unnecessary Android SDK checks.

* Remove unused accessors, skip replay test.

* Refactor platform_services sample

* removed exception

* Revert "use color.shadeXxx instead of color[Xxx] (#8932)"

This reverts commit 578ca0a2.

* Revert "add missing const keyword (#8931)"

This reverts commit fac2fac1.

* Revert "Make min/max fling velocity and min fling distance ScrollPhysics properties (#8928)"

This reverts commit dac80aac.

* Revert "Defer to operating system for whichAll (#8921)"

This reverts commit 14933de9.

* Revert "Update gradle wrapper and build-tools version for flutter create. (#8914)"

This reverts commit deb71cc6.

* use color.shadeXxx instead of color[Xxx]

* remove calls to .shade500 on MaterialColor

* remove calls to .shade200 on MaterialAccentColor

* fix test