Azure Monitor: Fix app insights source to allow for new __timeFrom and __timeTo (#21879)

* Fix app insights source to allow for new __timeFrom and __timeTo

* Try fixing the switch

pkg/tsdb/azuremonitor/macros.go

@@ -60,9 +60,9 @@ func (m *kqlMacroEngine) evaluateMacro(name string, args []string) (string, erro
 			timeColumn = args[0]
 		}
 		return fmt.Sprintf("['%s'] >= datetime('%s') and ['%s'] <= datetime('%s')", timeColumn, m.timeRange.GetFromAsTimeUTC().Format(time.RFC3339), timeColumn, m.timeRange.GetToAsTimeUTC().Format(time.RFC3339)), nil
-	case "__from":
+	case "__timeFrom", "__from":
 		return fmt.Sprintf("datetime('%s')", m.timeRange.GetFromAsTimeUTC().Format(time.RFC3339)), nil
-	case "__to":
+	case "__timeTo", "__to":
 		return fmt.Sprintf("datetime('%s')", m.timeRange.GetToAsTimeUTC().Format(time.RFC3339)), nil
 	case "__interval":
 		var interval time.Duration