Video integration tests timing out

[newmuis]

https://travis-ci.org/ampproject/amphtml/jobs/455599424

DESCRIBE => amp-video-iframe
  DESCRIBE => Video Interface
    IT => should override the video interface methods
      ✗ Error: Timeout of 20000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.
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  DESCRIBE => Analytics Triggers
    IT => should trigger pause analytics when the video pauses
      ✗ Error: Timeout of 20000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.
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    IT => should trigger session analytics when a session ends
      ✗ Error: Timeout of 20000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.
○○○●
    DESCRIBE => should trigger ended analytics
      IT => "before all" hook for "should trigger session analytics when a session ends"
        ✗ Error: Timeout of 20000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.
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  DESCRIBE => Autoplay
    DESCRIBE => play/pause
      IT => should play when in view port initially
        ✗ Error: Timeout of 20000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.
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      IT => should not play when not in view port initially
        ✗ Error: Timeout of 20000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.

[alanorozco]

Fixed in #19342