add roundIcon to Manifest

src/main/AndroidManifest.xml

@@ -58,6 +58,7 @@
     <application
         android:name=".MainApp"
         android:icon="@mipmap/ic_launcher"
+        android:roundIcon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:fullBackupContent="@xml/backup_config"
         android:theme="@style/Theme.ownCloud.Toolbar"