Don't destroy PlaybackSession on error to allow retrieve session id on error

[StaehliJ]

As a integrator I want to display the current session id when the player has an error. So the support team can ask for it.

Hints

Here is the API for session id extraction on Apple platforms.

Acceptance criteria

• PillarboxExoPlayer.getCurrentMetrics doesn't return null when player has an error.

Tasks

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