Add missing newline to build.gradle

Author: JeroenWeener

google_api_availability_android/android/build.gradle

@@ -41,4 +41,4 @@ android {
 dependencies {
     implementation 'com.google.android.gms:play-services-base:18.1.0'
     implementation 'androidx.annotation:annotation:1.1.0'
-}
+}