[webview_flutter] Bump version for republishing (flutter#3928)

The published version of 2.0.6 is not compatible with the current
Flutter stable (2.2) and earlier due to an issue with how Dart 2.14
(on the current Flutter master) creates archives. See
dart-lang/pub#3001

This is a no-op change to allow republishing from stable.

Fixes flutter/flutter#82803

Mark in_app_purchase as stable (flutter#3929)

[in_app_purchase] Add reference to the codelab in the README (flutter…

…#3896)

* Add reference to the codelab

* Updated version number

[espresso] Minor cleanup (flutter#3901)

Clean up webview readme (flutter#3900)

[image_picker] Image picker fix alert (flutter#3881)

Clean up webview readme (flutter#3900)

[in_app_purchase] update min Flutter version to 1.20.0 (flutter#3887)

[image_picker] Image picker fix metadata (flutter#3873)

This PR fixes a rotation problem where "Select Photos" limited access is chosen but the image that is picked is not included in selected photos and the image is scaled.

[in_app_purchase] Android example using in_app_purchase_android packa…

…ge (flutter#3861)

Adds the example app for the in_app_purchase_android platform implementation.

Adds the Android implementation for issue flutter/flutter#81695
NOTE: this PR builds on top of the "[in_app_purchase] Federated Android implementation" pull request. If have split in into a separate PR so it would be easier to review.