Update mw.KDPMapping.js

fix the fullscreen api
Merge remote-tracking branch 'origin/fixfullscreenbug' into 2.5-March-23
#FEC-1028 #time 3h #comment role should be on the body tag and not the IFrame tag. Setting the role on the IFrame tag causing IE8 to read all the content attributes when navigating to the IFrame using the arrow keys. Currently not setting role="application" on the body tag (in kalturaIframeClass.php) since this causes other issues in IE8. Since it was on the IFrame, it didn't work anyway.