Explicitly opt in to clearTextTraffic

According to docs, cleartext support is disabled by starting with Android 9.

Ref: https://developer.android.com/training/articles/security-config#CleartextTrafficPermitted

app/src/main/AndroidManifest.xml

@@ -8,6 +8,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
 
     <application
+        android:usesCleartextTraffic="true"
         android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"