Switch widgets away from android.text.format.Time

android.text.format.Time is limited to 32-bit seconds from the
beginning of the Unix epoch and so classes that use it are limited
to 1901 - 2038. Switching to java.time avoids this issue.

Manual Testing:

AnalogClock is deprecated and not used anywhere so difficult to
test.

DateTimeView is used in the status bar. Behavior was verified with
current date/time and also Europe/London around 2019-03-31 01:00
(skip forward) and around 2019-10-27 02:00 (fall back). The time picker
in settings uses android.icu.util.Calendar which favored the later time
if there are two local times with the same display time (e.g. the
fall back case). The "repeat" case was tested with "date @1572137900"
to set the clock to "the first" 01:58, then waiting 2 minutes to
ensure that the 01:59 -> 01:00 transition occurs correctly.

Bug: 16550209
Test: build / boot / treehugger
Test: See above
Change-Id: Ibadad3041a2e54fe12d347960bf1e0f3ebe10c01