Update data usage UX

Update the UX and dig the data usage screen out of a huge whole of
technical debt.  Switch every to use Preferences rather than standard
layouts and ListViews.

Split data usage into several fragments, all separated.

DataUsageSummary:
 - Shows a summary of the 'default' usage at the top, this will be
   the default sim on phones, or wifi if it has it, or ethernet
   as last attempt to show something.
 - Also has individual categories for each network type that has
   data, cell, wifi, and ethernet. Maybe should look into bt though?

DataUsageList:
- Takes a NetworkTemplate as an input, and can only be reached from
  the network specific categories in DataUsageSummary
- Shows a graph of current usage for that network and links to
  app detail page for any app.
- Has gear link to quick get to billing cycle screen if available

BillingCycleSettings:
 - Just a screen with the cycle day and warning/limits separated
   out from the data usage.

AppDataUsage:
 - App specific data usage details
 - May need some UX iteration given lack of clarity in the spec

Bug: 22459566
Change-Id: I0222d8d7ea7b75a9775207a6026ebbdcce8f5e46

src/com/android/settings/Utils.java

@@ -67,6 +67,7 @@ import android.telephony.TelephonyManager;
 import android.text.Spannable;
 import android.text.SpannableString;
 import android.text.TextUtils;
+import android.text.format.DateUtils;
 import android.text.style.TtsSpan;
 import android.util.ArraySet;
 import android.util.Log;
@@ -81,6 +82,7 @@ import android.view.animation.AnimationUtils;
 import android.widget.ListView;
 import android.widget.TabWidget;
 import com.android.internal.util.UserIcons;
+import com.android.settings.datausage.DataUsageList;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -91,6 +93,8 @@ import java.util.List;
 import java.util.Locale;
 
 import static android.content.Intent.EXTRA_USER;
+import static android.text.format.DateUtils.FORMAT_ABBREV_MONTH;
+import static android.text.format.DateUtils.FORMAT_SHOW_DATE;
 
 public final class Utils extends com.android.settingslib.Utils {
 
@@ -978,5 +982,19 @@ public final class Utils extends com.android.settingslib.Utils {
         context.getTheme().resolveAttribute(attr, value, true);
         return value.resourceId;
     }
+
+    private static final StringBuilder sBuilder = new StringBuilder(50);
+    private static final java.util.Formatter sFormatter = new java.util.Formatter(
+            sBuilder, Locale.getDefault());
+
+    public static String formatDateRange(Context context, long start, long end) {
+        final int flags = FORMAT_SHOW_DATE | FORMAT_ABBREV_MONTH;
+
+        synchronized (sBuilder) {
+            sBuilder.setLength(0);
+            return DateUtils.formatDateRange(context, sFormatter, start, end, flags, null)
+                    .toString();
+        }
+    }
 }