Remove old support lib proguard rules

AndroidX ships proguard rules that are automatically used

app/proguard-rules.pro

@@ -33,17 +33,6 @@
     public *;
 }
 
-# Samsung Android 4.2 bug
-# https://code.google.com/p/android/issues/detail?id=78377
--keepnames class !android.support.v7.internal.view.menu.**, ** {*;}
-
--keep public class android.support.v7.widget.** {*;}
--keep public class android.support.v7.internal.widget.** {*;}
-
--keep public class * extends android.support.v4.view.ActionProvider {
-    public <init>(android.content.Context);
-}
-
 # The rxjava library depends on sun.misc.Unsafe, which is unavailable on Android
 # The rxjava team is aware of this, and mention in the docs that they only use
 # the unsafe functionality if the platform supports it.