beckham: overlay: Consolidate rounded_corner_radius_* values

- Only set "rounded_corner_radius" being that the values for
  _top/_bottom are identical.

Change-Id: Id8b9025138d184bdf728b019c47d68f3ef267ec7

overlay/frameworks/base/core/res/res/values/dimens.xml

@@ -16,11 +16,6 @@
 */
 -->
 <resources>
-    <!-- Radius of the software rounded corners at the top of the display in its natural
-        orientation. If zero, the value of rounded_corner_radius is used. -->
-    <dimen name="rounded_corner_radius_top">15dp</dimen>
-
-    <!-- Radius of the software rounded corners at the bottom of the display in its natural
-        orientation. If zero, the value of rounded_corner_radius is used. -->
-    <dimen name="rounded_corner_radius_bottom">15dp</dimen>
+    <!-- Default radius of the software rounded corners. -->
+    <dimen name="rounded_corner_radius">15dp</dimen>
 </resources>