SQL Expression: Add instrumentation for sql expressions (#103758)

pkg/expr/transform.go

@@ -81,7 +81,7 @@ func (s *Service) TransformData(ctx context.Context, now time.Time, req *Request
 			respStatus = "failure"
 		}
 		duration := float64(time.Since(start).Nanoseconds()) / float64(time.Millisecond)
-		s.metrics.expressionsQuerySummary.WithLabelValues(respStatus).Observe(duration)
+		s.metrics.ExpressionsQuerySummary.WithLabelValues(respStatus).Observe(duration)
 
 		span.End()
 	}()