fix some lint warnings

- remove unused xml files in res/color
- fix messup in device_list.xml; sp was used instead of dp;
  textview not needed (no text), because just a divider for
  list parts.
- remove useless parent LinearLayout
- remove useless sub layouts (no id, no background, no children,
  no style)
- use Double.valueOf instead of new Double()
- modify Manifest of test and uitest package:
    disable warnings for ApplicationIcon and Backup