Extend LocalLog to enable UTC timestamps

Extend LocalLog to enable UTC timestamps with elapsed realtime clock
info too.

Switch time-related usages over to using UTC timestamps. This will make
debugging a lot easier when the code doing the logging is responsible
for changing the system clock and default time zone.

Test: treehugger only
Bug: 140712361
Change-Id: Ic6b12f9032c0c3ebc48f12a970a7b4dd398e7fec