fix for android build

android/build.gradle

@@ -34,7 +34,7 @@ android {
     }
     defaultConfig {
         minSdkVersion 16
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
     lintOptions {
         disable 'InvalidPackage'