Moved getting next alarm logic for alarm_clock icon to delayed updateAlarmIcon method

(Some clock apps send the ALARM_CHANGED broadcast before setting NEXT_ALARM_FORMATTED)
Fixed for devices with HTC Sense

updateAlarm method is in class HtcPhoneStatusBarPolicy
updateAlarm method has a slightly different handling of the alarm icon
Set update delay for updating the alarm icon to 100ms on HTC Sense devices

This is necessary as WorldClock is sending the ALARM_CHANGED broadcast before setting NEXT_ALARM_FORMATTED
Re-use class HtcPhoneStatusbarPolicy as HTC Sense devices