Add metrics and crash key for ScreenAI service when OCR is used.

OCR process of ScreenAI service uses a lot of memory and one of the
largest categories of its crashes is OOM.
To get appropriate thresholds to disable the service or use a lighter
one, add crash keys to the service, and metrics to record available and
total memory and pressure level before launching the service, separated
for cases where there service crashes and shuts down.

AX-Relnotes: n/a
Bug: 397258336
Change-Id: I7b9bffa56c05230f4e6cb27012e629e448fde81f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6348738
Reviewed-by: Luc Nguyen <lucnguyen@google.com>
Auto-Submit: Ramin Halavati <rhalavati@chromium.org>
Reviewed-by: Tzarial <zork@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1431948}