fix: ContainerLog.ToEvent honors Level [FOUNDENG-370] (determined-ai#…

…5558)

When manually sending an ContainerLog event to the Allocation, the Level field is ignored and resets to nil.   Propagate the Level field to the task.Event so that
the caller has control over the Level.

master/internal/sproto/task_actor.go

@@ -83,6 +83,7 @@ func (c ContainerLog) ToEvent() Event {
 		ContainerID: c.ContainerID.String(),
 		Time:        c.Timestamp.UTC(),
 		LogEvent:    ptrs.Ptr(c.Message()),
+		Level:       c.Level,
 	}
 }