feat: add a default audio codec for the HLS video player

[nsprenkle]

Description

Some HLS video sources, when performing a level switch from default starting bitrate to a different bitrate encounter an error which causes garbled audio.

Defining a default audio codec seems to reduce this occurrence. See the docs which note that omitting a default value can cause issues.

NOTE that the real fix is probably to update our now five years out-of-date HLS library version but that is a whole other conversation for a different day and can probably just be deferred to extraction of the video block.

Testing instructions

1. Load a known broken video. These are often from outside sources like private YouTube videos or CloudFront hosted files.
2. Before fix, at the 10 second mark the video should perform a level switch and cause broken audio.
3. After fix, there should be no breakage to audio.

[Copilot]

Pull Request Overview

This PR adds a default audio codec configuration for the HLS video player to prevent garbled audio issues that can occur during bitrate level switches. The change sets mp4a.40.5 (HE-AAC) as the default audio codec when not explicitly provided in the configuration.

• Sets a default audio codec (mp4a.40.5) for HLS playback to reduce audio corruption during level switches
• Implements the fix as a temporary measure while acknowledging that updating the outdated HLS.js library (v0.14.17) would be the proper long-term solution

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