Remove unneeded margin below action bar subtitles

This just throws off alignment when the natural centering of this
layout will take care of things.

Bug 6369593

Change-Id: If0993091e0d47011f3bf5dd0b5a1fa649471f8e6

Author: adamp

core/res/res/layout/action_bar_title_item.xml

@@ -42,7 +42,6 @@
                   android:layout_width="wrap_content"
                   android:layout_height="wrap_content"
                   android:layout_marginTop="@dimen/action_bar_subtitle_top_margin"
-                  android:layout_marginBottom="@dimen/action_bar_subtitle_bottom_margin"
                   android:singleLine="true"
                   android:ellipsize="end"
                   android:visibility="gone" />