Associated feature: T292887: Add an image: captions onboarding dialog
When the user advances to the caption step by selecting "yes" on the image inspector, they may see the captions onboarding dialog depending on whether they have chosen "don't show this again" in the past. We want to record events for these actions:
- Impression of the dialog
- Closing the dialog.
- This event should store whether the "don't show this again" checkbox was selected at the time it was closed.
- From where the dialog was opened. It comes from two places, and we want to record which one it came from:
- Arrival on the caption step
- Selecting the question mark icon during the caption step