Fix missing Kotlin dependency

[toteto]

When building for Android, I was getting this error when trying to use this plugin.

Initializing gradle...                                       0.9s
Resolving dependencies...
* Error running Gradle:
Exit code 1 from: /Users/aivanovs/data/flutter_girl/android/gradlew app:properties:
Failed to notify ProjectEvaluationListener.afterEvaluate(), but primary configuration failure takes precedence.
java.lang.IllegalStateException: compileSdkVersion is not specified.

* Where:
Build file '/Users/aivanovs/.pub-cache/hosted/pub.dartlang.org/barcode_scan-0.0.3/android/build.gradle' line: 27

* What went wrong:
A problem occurred evaluating project ':barcode_scan'.
> Plugin with id 'kotlin-android' not found.```