Show the proper time zone name based on whether event start time is in DLS or not

e.g. Eastern Standard Time vs Eastern Daylight Time

- Fixed the same when picking a home time zone
- Also fixed the problem where moving switching from all day to non-all day
  will put the event in device time zone instead of app time zone
- Updated the list of tz to match Settings
- Added sun symbol to denote the tz observes DLS
- Improve performance by lazily generate all the display time zone names.

Bug: 6187750
Change-Id: Iaba77590c4b1062d41fbdd8f2368a7e64836f113