Previously we only enable `SeekParameter.*_SYNC` for HLS when `EXT-X-INDEPENDENT-SEGMENTS` is set in the playlist. However, this condition can actually be loosened. To seek in HLS, we need to download the segment in which the resolved seek position locates under any circumstance. If `SeekParameter.PREVIOUS_SYNC` or `SeekParameter.CLOSEST_SYNC` is passed, and that segment happens to start with sync samples, then the seek can be done quicker with that adjusted seek position. And if that segment doesn't start with sync samples, then the behaviour will be the same as we set the adjusted seek position to the exact original position. But we still cannot safely enable `SeekParameter.NEXT_SYNC` as it will potentially cause the seeking to miss more content than seeking to the exact position.
Issue: androidx/media#2209
PiperOrigin-RevId: 737580861
42b71c29e8