[downloader/hls] Disable decryption in tests (#27660)
[downloader/hls] Disable decryption in tests (#27660)

Tests truncate the download to 10241 bytes, which is not divisible by 16
and cannot be decrypted. Tests don't really care about the decrypted
content, just that the data they retrieved is the expected data.
Therefore, it's fine to just return the encrypted data to tests.

See: #27621 and #27620
Tatsh/youtube-dl,ozburo/youtube-dl,rg3/youtube-dl,rg3/youtube-dl,ozburo/youtube-dl,Tatsh/youtube-dl