Playback: speed changes from 1.0 to 1.5

Grouping reports of users playing an episode at playback speed 1.0 and suddenly changing to 1.5

In all these cases, users are listening using a Bluetooth headset, and debug logs show `Remote control: changePlaybackRateCommand`

#4806411-zen

#5176174-zen

#5301102-zen

Start by tracing the iOS handling for the logged `changePlaybackRateCommand` when a Bluetooth headset is connected; the issue names no file or test. Reproduce the reported transition from playback speed 1.0 to 1.5 and use the linked support reports and debug log wording as reference. Done means the playback speed no longer changes unexpectedly in this scenario.

Written by the indexing model from the issue text.