updateAccessibilityState

Re-reads what a screen reader should say about the player and tells the platform.

This view calls it when the player is assigned, and while it is on screen, each time the player's status or duration changes. It does not follow the position, because a value that changed on every tick would make a screen reader speak continuously. So the position read out is the one from the last change. An application that wants a fresh position, for example after a seek, calls this beside its own controls.