Use selectable to set focusable on root pref view

b/24771938

Change-Id: I65d7c4ba67d970c944230d5ccfcd6b4cb9fa32c5
diff --git a/v7/preference/src/android/support/v7/preference/Preference.java b/v7/preference/src/android/support/v7/preference/Preference.java
index 84ab3b3..aa37ac8 100644
--- a/v7/preference/src/android/support/v7/preference/Preference.java
+++ b/v7/preference/src/android/support/v7/preference/Preference.java
@@ -517,8 +517,11 @@
             setEnabledStateOnViews(holder.itemView, true);
         }
 
-        holder.setDividerAllowedAbove(isSelectable());
-        holder.setDividerAllowedBelow(isSelectable());
+        final boolean selectable = isSelectable();
+        holder.itemView.setFocusable(selectable);
+
+        holder.setDividerAllowedAbove(selectable);
+        holder.setDividerAllowedBelow(selectable);
     }
 
     /**