[Memory Panel] Fix canvasChartWidth has not been initialized error when changing the zoom duration (#9573)

Author: elliette

packages/devtools_app/lib/src/screens/memory/panes/chart/widgets/interval_dropdown.dart

@@ -43,10 +43,11 @@ class _IntervalDropdownState extends State<IntervalDropdown> {
           );
           widget.chartController.data.displayInterval = value;
           final duration = value.duration;
-
           widget.chartController.event.zoomDuration = duration;
           widget.chartController.vm.zoomDuration = duration;
-          widget.chartController.android.zoomDuration = duration;
+          if (widget.chartController.isAndroidChartVisible.value) {
+            widget.chartController.android.zoomDuration = duration;
+          }
         });
       },
       items: displayTypes,

packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md

@@ -32,7 +32,8 @@ TODO: Remove this section if there are not any general updates.
 
 ## Memory updates
 
-TODO: Remove this section if there are not any general updates.
+- Fixed error preventing users from changing the zoom duration. -
+  [#9573](https://github.com/flutter/devtools/pull/9573)
 
 ## Debugger updates