Tweak logged info for time / time zone detection

Tweak logged info for time / time zone detection: This reduces the
amount of history stored for bug reports to limit memory usage (it
can be increased again later if needed) and tries to make better
use of the history that is kept.

Bug: 140712361
Test: build / boot / dumpsys
Change-Id: I46b05eae77aac6d2a804cb6f3f6184772583f268