Clicking the "Mute" and "Unmute" buttons while the player is in error view state wrongly sends pings to telemetry

[SoftVision-CarmenFat]

[Affected versions]:

• Firefox Developer Edition 59.0b7
• Firefox Nightly 60.0a1 (02/08/2018)
• Min-Vid Shield Study Onboarding 0.4.7 - Shield Study

[Affected Platforms]:

• All Windows

[Prerequisites]:

• Latest Min-Vid v.0.4.7 Shield Study Onboarding ("active" or "activeAndOnboarding" variant) was previously installed on a clean profile.

[Steps to reproduce]:

1. Open the browser with the profiles from prerequisites and navigate to YouTube.
2. Send a video to the mini player that is embedded.
3. Click the "Mute" button from the player.
4. Click on the "Unmute" button.
5. Go to "about:telemetry" and observe if any ping related to the "mute" and "unmute" method is displayed.

[Expected result]:

• No pings related to "muting/unmuting" methods are sent to the telemetry.

[Actual result]:

• Pings that contain the "mute/unmute" methods are sent to telemetry.

[Notes]:

• Since there is no video in the error state view, there is no point on which users should use the volume button. By allowing this to still happen, in the end, this could lead to erroneous metrics results.
• Here is a screen recording of the issue:

[SoftVision-CarmenFat]

This issue is no longer reproducible on the latest Shield Study build.