mars: overlay: import screen dim brightness from stock

Change-Id: I8feacfc23b7e697653c1be29346361e35de5586d
Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>

overlay/frameworks/base/core/res/res/values/config.xml

@@ -394,6 +394,11 @@
          that can be set by the user. -->
     <integer name="config_screenBrightnessDoze">17</integer>
 
+    <!-- Screen brightness used to dim the screen when the user activity
+         timeout expires.  May be less than the minimum allowed brightness setting
+         that can be set by the user. -->
+    <integer name="config_screenBrightnessDim">13</integer>
+
     <!-- The bounding path of the cutout region of the main built-in display.
          Must either be empty if there is no cutout region, or a string that is parsable by
          {@link android.util.PathParser}.