Clean up EAS -> TimeZone determination code

* Use one minute before/after for transition checking, instead of the
  sloppier early version
* Add tests for additional known time zones
* Change most methods in CalendarUtilities to package private (for use
  with unit tests)
* Clean up a little bad formatting

Change-Id: I9e5be5e1c859f2294adf06874459f7db15fb8c22
2 files changed