Add more timestamps to dumpsys

Having the current elapsed realtime / system clock time close to the
time / time zone logs makes it easier to understand the age of the log
entries. This information is available elsewhere but this makes it
easier when interpreting the log entries immediately below.

Bug: 149014708
Test: treehugger
Change-Id: I29209746f1ebbb00e43c4477d0265a87243abd3b