Fix hardcoded px dimensions in "dialpad chooser" UI.

In the "dialpad chooser" UI (which comes up if you launch the Dialer while
a call is already in progress) the 3 items are too tightly spaced on WVGA
devices.  Fixed by changing the relevant dimensions from px to dp.

BUG=2185527
TESTED: got into the "chooser" state on a WVGA phone, confirmed the items
        are now sized correctly.
diff --git a/res/layout-finger/dialpad_chooser_list_item.xml b/res/layout-finger/dialpad_chooser_list_item.xml
index c5abeac..c836f5d 100644
--- a/res/layout-finger/dialpad_chooser_list_item.xml
+++ b/res/layout-finger/dialpad_chooser_list_item.xml
@@ -21,8 +21,8 @@
     android:layout_height="fill_parent">
 
     <ImageView android:id="@+id/icon"
-        android:layout_width="64px"
-        android:layout_height="64px"
+        android:layout_width="64dp"
+        android:layout_height="64dp"
         android:scaleType="center" />
 
     <TextView android:id="@+id/text"