CameraRecordingUtils: PictureCaptured Unity event is called before the image actually is captured

`m_PictureCaptured.Invoke()` is called `OnPhotoModeStarted`, but the image is not finished capturing before `onCapturedPhotoToDisk`.

```c#
....
// line 102
m_PictureCaptured.Invoke();
if (saveImage) SaveImage();
...
```

Start in CameraRecordingUtils around line 102 and trace the ordering of m_PictureCaptured.Invoke(), SaveImage(), and onCapturedPhotoToDisk. Reproduce the Unity photo-capture flow, then verify that PictureCaptured is raised only after the image has finished capturing and is available on disk.

Written by the indexing model from the issue text.