mesh-self-check: give D-fill's written-finding fixture its severity, so the row keeping a fill between the thresholds reads the finding it wrote (issue 1952)

modules/mesh-self-check/cmd/mesh-self-check/probes_test.go

@@ -257,7 +257,7 @@ func machines() *memStore {
 // filling is a store holding the self-check's written fill finding of a stream: the condition open.
 func filling(stream string) *memStore {
 	s := newStore()
-	o := Observation{Kind: "bucket-or-log-filling", Token: "filling", Subject: Subject{Scope: ScopeBus, ID: stream},
+	o := Observation{Kind: "bucket-or-log-filling", Token: "filling", Severity: Warning, Subject: Subject{Scope: ScopeBus, ID: stream},
 		Summary: "filling", Source: "D-fill"}
 	raw, _ := health.EncodeFinding(o.Finding("run", time.Now()))
 	_ = s.Put(FindingsState, o.Key(), json.RawMessage(raw))