STORM-289 FIXED browser navigation bar layout to make it resize properly after minimize/restore.

When floater media browser is minimized its button bars are shrunk to zero height and their height is not restored upon unminimizing because they have auto_resize disabled. Setting min_height for the button bars makes them restored with this height upon uminimizing the floater.

indra/newview/skins/default/xui/en/floater_media_browser.xml

@@ -33,6 +33,7 @@
          height="20"
          layout="topleft"
          left="0"
+         min_height="20"
          name="nav_controls"
          top="400"
          user_resize="false"
@@ -106,6 +107,7 @@
          height="20"
          layout="topleft"
          left_delta="0"
+         min_height="20"         
          name="time_controls"
          top_delta="0"
          user_resize="false"
@@ -163,6 +165,7 @@
          height="20"
          layout="topleft"
          left_delta="0"
+         min_height="20"         
          name="parcel_owner_controls"
          top_delta="0"
          user_resize="false"