keycreate: animate layout when revert button is pushed

OpenKeychain/src/main/res/layout/create_key_final_fragment.xml

@@ -14,7 +14,8 @@
             android:layout_height="wrap_content"
             android:paddingLeft="16dp"
             android:paddingRight="16dp"
-            android:orientation="vertical">
+            android:orientation="vertical"
+            android:animateLayoutChanges="true">
 
             <TextView
                 android:layout_width="match_parent"