Change day group header label in recents to medium weight.

Bug: 15408691
Change-Id: Id54cfac084a0ec0e80704ba602f32dfff544b4f8
diff --git a/res/layout/call_log_list_item.xml b/res/layout/call_log_list_item.xml
index 9a90b24..411af70 100644
--- a/res/layout/call_log_list_item.xml
+++ b/res/layout/call_log_list_item.xml
@@ -30,6 +30,7 @@
         android:layout_height="wrap_content"
         android:layout_marginStart="@dimen/call_log_start_margin"
         android:layout_marginEnd="@dimen/call_log_outer_margin"
+        android:fontFamily="sans-serif-medium"
         android:textColor="?attr/call_log_secondary_text_color"
         android:textSize="@dimen/call_log_secondary_text_size"
         android:paddingTop="@dimen/call_log_day_group_padding"