A player might emit a play signal before its duration is known.
We want to avoid controlling short sounds (e.g. chat notifications) but I found the duration often is NaN on first invication when the sound is loaded for the first time.
Defer activating the player until we get a durationchange event for that player

• No longer have it trying to control Facebook Messenger notification sounds
• YouTube still works fine
• Some random music stream (duration of Infinity) still works
• HTML Media sessions example (both video and audo) still work fine