bootanlyze: fix occasional wrong calculation of bootup time

- kernel bootcomplete and logcat bootcomplete sometimes had big gap
  and assumption of both being close were not correct.
- always collect kernel boot complete from logcat and use it.
- also use bootanim end as interim diff indicator if it is available.

bug: 33210752
Test: python packages/services/Car/tools/bootanalyze/bootanalyze.py -r -c packages/services/Car/tools/bootanalyze/config.yaml -n 10
Change-Id: I4ce55ee3a0d818ee951710bad77a5368640aa47b
1 file changed