fix(ios): preserve playback speed after pause/resume and audio interruptions

[notsuhas]

Summary

• Fix playback speed resetting to 1.0x on resume — AVPlayer.play() implicitly sets rate = 1.0, discarding the stored currentPlaybackSpeed
• Fix the same issue in the audio interruption handler (e.g., phone call, Siri), where speed was also lost on resume
• Update updateNowPlayingInfo calls to use currentPlaybackSpeed instead of hardcoded 1.0 so lock screen controls reflect the correct rate

Root Cause

AVPlayer.play() is equivalent to setting rate = 1.0. Both resume() and the interruption-ended handler called player?.play() without restoring the custom
rate afterward.

Android is unaffected — Media3's play() sets playWhenReady = true without changing PlaybackParameters.

Test plan

• Play audio, set speed to 1.5x or 2x
• Pause, then resume — speed should remain at the set value
• While playing at non-1.0 speed, trigger an audio interruption (e.g., Siri) and verify speed is preserved after interruption ends
• Verify lock screen now-playing info shows the correct playback rate

[notsuhas]

@bradfloodx please do check this