Voice Fill overlay behaves incorrectly if closing the "Warming up..." overlay too early

[SoftVision-CarmenFat]

[Affected versions]:

• Firefox 57 and up
• Voice Fill v.1.3.5

[Affected Platforms]:

• All Windows
• All Linux
• All Mac

[Prerequisites]:

• Have a Firefox profile with the Voice Fill (v. 1.3.5) experiment installed.
• Tools -> Permissions -> "Use default" is unchecked and "Allow" is checked.

[Steps to reproduce]:

1. Open the browser with the profile from prerequisites and navigate to a supported website.
2. Click the "Voice Fill" button from the right side of the search input.
3. Press "ESC" key while "Warming up" overlay is displayed.
4. Click again the "Voice Fill" button from the right side of the search input and observe the overlay displayed.

[Expected result]:

• A new recording session starts with "Warming up" overlay displayed.

[Actual result]:

• A new recording session starts with "Listening..." overlay displayed.

[Notes]:

• This issue is intermittent.
• Strange behavior is also happening when the permission for the microphone is blocked: the "Please enable your microphone to use Voice Fill" is displayed at first, skipping the "Warming up" overlay.
• Attached a screen recording of the issue: