Missing controls on iOS when switching back to html5 tech

[tomsaffell]

To recreate

1. setup vjs with 'controls' attr in video tag
2. via js, play an asset with a non-html tech (e.g. youtube)
3. via js, play an asset with html tech

Observed

At 3, there are no controls

Expected

At 3, there should be iOS native controls for the video

Fix

html5.js has

// Update specific tag settings, in case they were overridden
 var attrs = ['autoplay','preload','loop','muted'];

The 'controls' is not present, presumably because often times we dont want a controls attr in the video tag. I suggest a fix of:

if (player.options_.controls && player.options_['customControlsOnMobile'] !== true && (vjs.IS_IOS || vjs.IS_ANDROID)) {
attrs.push('controls');
}