This reverts commit 59bb2dba.

Uses the `version` property from the `pubspec.yaml` file to set the corresponding fields in the `local.properties` file respectively in the `Generated.xcconfig` file.

The `--build-name` and `--build-number` options have changed. Now they trump the `version` property from the `pubspec.yaml` file.

If the `version` property is not set and the  `--build-name` and `--build-number` options are not provided, the build command will not change the `local.properties` / `Generated.xcconfig` file.

This reverts commit 0f557e72.

This reverts commit dac1baf4.

Fixes https://github.com/flutter/flutter/issues/13972

Remove terminating semicolons; they are causing an "code inspection warning" in Android Studio:

```
This inspection reports redundant semicolon (';') token which is not required in Kotlin and may be removed.
```

Going forward, Android support libraries are published on maven (instead of bundling them with the SDK). Many plugins depend on these. To avoid requiring plugin users to add the maven repository to their app this change adds the repository to the template for `flutter create`.

This also bumps the support-annotations dependency to 25.4.0 (which also requires the new maven repository).