metrics: add TPM.EarlyResetDuringCommand CrOS event.

This is reported if the TPM was reset during a command
in the first 30 seconds of the previous boot session.

BUG=chromium:431360
TEST=none
BRANCH=none

Change-Id: I66fb453094e5281301cb39d9b86ba5f9c82c10f6
Reviewed-on: https://chromium-review.googlesource.com/261357


Tested-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-by: Darren Krahn <dkrahn@chromium.org>
Commit-Queue: Luigi Semenzato <semenzato@chromium.org>