[TIMOB-18158] iOS: Volume of video player does not change when controlled by slider

The volume of the video does not change when the position of the slider that controls the volume changes. According to the docs, the volume of the video player also controls the volume of the device. When the video in the attached sample app starts playing, the slider is shown to be at the maximum regardless of the volume of the device. When the device volume is not muted, the video starts playing with a volume, when it should actually be muted, and increasing the volume of the video via the slider has no effect. Currently the volume of the video is only controlled by the device volume (controlling using the hardware buttons). This is a regression as it works as expected with titanium sdk 3.4.1 Steps to reproduce: 1. Create a sample and include 'movie.mp4' under resources and replace app.js with the attached one 2. run app on device 3. Move the slider position towards the right 4. Move the slider position towards the left Actual results: 2. Video starts playing with maximum value shown on the slider for the volume regardless of the volume set on the device. If device volume is not muted, the video plays with sound. 3. no change in the volume of the video 4. no change in the volume of the video Expected results 2. Video should start playing without any sound, and the slider position should be at minimum, regardless of the device volume. The volume (speaker symbol) pops up showing that the volume has been muted. 3. volume of the video should increase and this should also increases the volume of the device. 4. volume of the video should decrease and the volume of the device should also decrease and should be muted when the slider reaches the end on the left.