## Issue
5554: Video: loading circle sometimes does not appear until 2nd click
## What's happening
videojs behavior:
(a) A `src` change makes the Play button re-appear.
(b) An `onPlay` (or `play()`) makes the button go away.
Due to the `m3u8` header async fetch (i.e. return is potentially delayed), the initial `onPlay` (which cleared the button) that happened after user clicked Play gets negated by a potentially-delayed `src` change.
# Changes
- Manually hide the play button that is induced by the change in `src`. In the fetch-delay scenario mentioned above, the player continues to be in a 'playing' state anyway.
- But don't hide the button if paused externally (e.g. browser-level)
Restore video loading circle
05383701af