Refactored AbstractFragment to not depend on AbstractInfoFragment (#487)

Due to a previous refactoring, dataHolder was still of type
AbstractInfoFragment.DataHolder which should be just DataHolder
in AbstractFragment. Although AbstractInfoFragment inherits from
AbstractFragment the code works. However, on KitKat (4.4) some
devices reported a missing method which might be caused by this "weird"
inheriting. Hopefully this fixes that.

app/src/main/java/org/xbmc/kore/ui/AbstractFragment.java

@@ -22,9 +22,9 @@
 
 public class AbstractFragment extends Fragment {
 
-    private AbstractInfoFragment.DataHolder dataHolder;
+    private DataHolder dataHolder;
 
-    public void setDataHolder(AbstractInfoFragment.DataHolder dataHolder) {
+    public void setDataHolder(DataHolder dataHolder) {
         this.dataHolder = dataHolder;
         Bundle bundle = getArguments();
         if (bundle == null) {
@@ -34,7 +34,7 @@ public void setDataHolder(AbstractInfoFragment.DataHolder dataHolder) {
         }
     }
 
-    public AbstractInfoFragment.DataHolder getDataHolder() {
+    public DataHolder getDataHolder() {
         return dataHolder;
     }
 
@@ -43,7 +43,7 @@ public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
         if( this.dataHolder == null ) {
-            this.dataHolder = new AbstractInfoFragment.DataHolder(-1);
+            this.dataHolder = new DataHolder(-1);
         }
 
         this.dataHolder.setBundle(getArguments());