Switch code 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.

Bug: 16550209
Test: build / boot / treehugger
Change-Id: Ibf56b32a78e8aad71fb1738ccd61b32a03fe0156