Fix android extensions maven dependencies

`kotlin-android-extensions-runtime` and `kotlin-android-extensions-compiler`
had `com.google.android:android` as a provided dependency, but
during transition to Kotlin Gradle build the dependency was declared
as `runtime` instead of `compileOnly`.

prepare/android-extensions-compiler-gradle/build.gradle.kts

@@ -14,7 +14,7 @@ dependencies {
     compileOnly(project(":compiler:backend"))
     compileOnly(project(":kotlin-android-extensions-runtime"))
     runtime(projectRuntimeJar(":kotlin-compiler-embeddable"))
-    runtime(commonDep("com.google.android", "android"))
+    compileOnly(commonDep("com.google.android", "android"))
 }