Various proc stats UI improvements.

- Option to include system processes.
- Option to use uss instead of pss sizes.
- Option to select type of stats: background processes, foreground (top)
  processes, cached processes.
- Details now shows max mem usage.

Change-Id: Ic994564ce846bc1021bf35576feeb9ef095b0e48

src/com/android/settings/fuelgauge/PowerUsageDetail.java

@@ -333,7 +333,7 @@ public class PowerUsageDetail extends Fragment implements Button.OnClickListener
                         mUsesGps = true;
                         // Fall through
                     default:
-                        value = Utils.formatElapsedTime(getActivity(), mValues[i]);
+                        value = Utils.formatElapsedTime(getActivity(), mValues[i], true);
                 }
                 ViewGroup item = (ViewGroup) inflater.inflate(R.layout.power_usage_detail_item_text,
                         null);