Downgrade Android Gradle Plugin

- AGP 4.2 is not compatible with IntelliJ yet (see:
  https://issuetracker.google.com/issues/187326587?pli=1)

build.gradle.kts

@@ -5,7 +5,7 @@ buildscript {
   }
 
   dependencies {
-    classpath("com.android.tools.build:gradle:4.2.0")
+    classpath("com.android.tools.build:gradle:4.1.0")
     classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.72")
   }
 }