Clicking on QC header expands the header

* The maximum expansion size of the image is equal to its width.
* For the minimum header size. We now rely on android.R.attr.actionBarSize
  instead of using a value in dimens.

Change-Id: I9e2438a457bd2afc50f07d028c810efc8455678e
diff --git a/res/layout/quickcontact_activity.xml b/res/layout/quickcontact_activity.xml
index a7c12dd..8f78811 100644
--- a/res/layout/quickcontact_activity.xml
+++ b/res/layout/quickcontact_activity.xml
@@ -26,7 +26,7 @@
 
     <FrameLayout
         android:layout_width="match_parent"
-        android:layout_height="@dimen/quickcontact_maximum_header_height"
+        android:layout_height="match_parent"
         android:layout_marginTop="@dimen/quickcontact_starting_empty_height"
         android:background="@color/card_margin_color"
         android:id="@+id/toolbar_parent">