fix(FEC-8652): 'open full screen' icon changed to 'exit full screen' icon when entering picture in picture on iPad

[odedhutzler]

Description of the Changes

issue: when entering PIP the fullscreen icon is changed to 'exit from full screen'. this happens because Safari raises a webkitbeginfullscreen when it enters picture-in-picture mode.

solution: before going to full screen, check if we are already in PIP.

Issue reference in webkit: https://bugs.webkit.org/show_bug.cgi?id=191629

CheckLists

• [ ] changes have been done against master branch, and PR does not conflict
• [ ] new unit / functional tests have been added (whenever applicable)
• [ ] test are passing in local environment
• [ ] Travis tests are passing (or test results are not worse than on master branch :))
• [ ] Docs have been updated

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This change is 

[kaltura-hooks]

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[OrenMe]

webkit bug is now merged into patch at https://bugs.webkit.org/show_bug.cgi?id=215972