Replaces the tunable configuration of one seeded condition: whether it is evaluated,
its threshold, its dwell and its cooldown.

The condition KEY and its SEVERITY are not settable. A settable severity would let a
destination's severity filter be bypassed by editing the condition instead of the
destination — the same authorization decision expressed in two places, which is how
the two come to disagree.

Disabling a condition that is currently FIRING closes it: resolved_at is set and one
RESOLVED notification is emitted. Left open it would sit firing in the console forever,
because nothing evaluates it any more.

Authorization: admin.platform.alerts.write.