Fix secondary data usage color regression.

Show overall usage with a 50% transparency when looking at a
specific app details page.  (Otherwise you can't tell them apart.)

Bug: 18927935
Change-Id: I0cad1ba0451a9dab3ed90fa5aa53c115dbe3e1d3
diff --git a/src/com/android/settings/DataUsageSummary.java b/src/com/android/settings/DataUsageSummary.java
index f2a2257..ce68e3d 100644
--- a/src/com/android/settings/DataUsageSummary.java
+++ b/src/com/android/settings/DataUsageSummary.java
@@ -841,8 +841,10 @@
             }
         }
 
-        mSeries.setChartColor(Color.BLACK, seriesColor, seriesColor);
-        mDetailedSeries.setChartColor(Color.BLACK, seriesColor, seriesColor);
+        final int secondaryColor = Color.argb(127, Color.red(seriesColor), Color.green(seriesColor),
+                Color.blue(seriesColor));
+        mSeries.setChartColor(Color.BLACK, seriesColor, secondaryColor);
+        mDetailedSeries.setChartColor(Color.BLACK, seriesColor, secondaryColor);
     }
 
     private boolean isAppDetailMode() {