b/3054044 Make allDay event times format in utc

AllDay events could get formatted with the local time zone
instead of utc. This makes it so that using the utc flag in the
wrapper for formatting correctly passes in UTC as the time zone.

Change-Id: I65090ef939ce64c1a942c7683cf76a927c02cb53

core/java/android/util/CalendarUtils.java

@@ -146,6 +146,9 @@ public class CalendarUtils {
          * This formats a date/time range using Calendar's time zone and the
          * local conventions for the region of the device.
          *
+         * If the {@link DateUtils#FORMAT_UTC} flag is used it will pass in
+         * the UTC time zone instead.
+         *
          * @param context the context is required only if the time is shown
          * @param startMillis the start time in UTC milliseconds
          * @param endMillis the end time in UTC milliseconds
@@ -156,10 +159,16 @@ public class CalendarUtils {
         public String formatDateRange(Context context, long startMillis,
                 long endMillis, int flags) {
             String date;
+            String tz;
+            if ((flags & DateUtils.FORMAT_UTC) != 0) {
+                tz = Time.TIMEZONE_UTC;
+            } else {
+                tz = getTimeZone(context, null);
+            }
             synchronized (mSB) {
                 mSB.setLength(0);
                 date = DateUtils.formatDateRange(context, mF, startMillis, endMillis, flags,
-                        getTimeZone(context, null)).toString();
+                        tz).toString();
             }
             return date;
         }