Icons disappeared  after Dexguard shrinking and obfuscation.
I am using `com.mikepenz:material-design-iconic-typeface:2.2.0.1@aar` and iconcis 2.5.11. It works in debug build. But in release build after dexguard shrinking and obfuscation. All icons disappeared.

I already added those rules to my dexguard file

```
-keep class .R
-keep class **.R$* {
    <fields>;
}
-keep class com.mikepenz.material_design_iconic_typeface_library.MaterialDesignIconic { *; }
```

Dexguard version: 7.1.26
