test(Tizen): Skip high playbackRate test to avoid Tizen decoder bug
test(Tizen): Skip high playbackRate test to avoid Tizen decoder bug

The high playbackRate test seems to trigger a Tizen 3 platform bug in
which the decoders fail when the playback rate is above 2x.  We can't
control this as far as I can tell, so this change skips the test on
Tizen.

Found while investigating #2620.

Change-Id: I5b72005c9539c3945dad2cdd7eced8649d7a9cb6

tvoli/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,tvoli/shaka-player,tvoli/shaka-player