lmkd: Change meminfo_log into killinfo_log and log additional fields

meminfo_log is used to log the state of the memory at the time of a kill.
Instead of reporting kill information and meminfo separately let's combine
them into one killinfo_log report. While normal logs can be trimmed by
chatty, meminfo_log uses a separate log context which gives it a better
chance of survival. As a result we will have all the information relevant
to a kill in one report which has higher chance of surviving chatty.

Bug: 74119935
Test: lmkd_unit_test
Change-Id: I83a9c12d538e1fb107721b04fdafc3c6c0d83b60
Signed-off-by: Suren Baghdasaryan <surenb@google.com>