Add a new android course (#6615)

courses/free-courses-en.md

@@ -143,6 +143,7 @@
 * [Developing Android Apps with Kotlin](https://www.udacity.com/course/developing-android-apps-with-kotlin--ud9012) - (Udacity)
 * [Firebase in a Weekend: Android](https://www.udacity.com/course/firebase-in-a-weekend-by-google-android--ud0352) - (Udacity)
 * [Gradle for Android and Java](https://www.udacity.com/course/gradle-for-android-and-java--ud867) - (Udacity)
+* [Jetpack Compose](https://www.youtube.com/playlist?list=PLQkwcJG4YTCSpJ2NLhDTHhi6XBNfk9WiC) - Philipp Lackner
 * [Kotlin Bootcamp for Programmers](https://www.udacity.com/course/kotlin-bootcamp-for-programmers--ud9011) - (Udacity)
 * [Learn Android Application Development for Beginners](https://www.udemy.com/course/learn-android-application-development-y/) - Johan Jurrius, ProgramMe Programming (Udemy)
 * [Learn how to program: Android](https://www.learnhowtoprogram.com/android) - Epicodus Inc.