Fix SimpleDateFormatTest when run outside California

If the device was set to a timezone besides America/Los_Angeles
the test would fail. Under cts-tradefed the SimpleDateFormat
was being created at class load time (using the device default)
and then the timezone default was being set to
America/Los_Angeles during setUp().

Contains refactoring to remove nested test case and
reformatting.

(cherry picked from commit a4b67b6f5ba9d233023c55c816121070770e4ac5)

Change-Id: I6bde5cd3459f94a9224b330e2d1e69ebecda6a4c
1 file changed