Misc fix for secondary user

- Theme fix: action bar and status bar color now have enough contrast
  for SUW theme.
- Fix a ConcurrentModificationError when switching between users
  quickly.

Change-Id: If31f88e36f1d4c5d7f90bc9d128041f0e0a81ff9
Fix: 35948464
Test: make RunSettingsRoboTests

tests/robotests/src/com/android/settings/SettingsActivityTest.java

@@ -21,6 +21,7 @@ import android.app.FragmentManager;
 import android.app.FragmentTransaction;
 import android.content.Intent;
 import android.graphics.Bitmap;
+
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;