How to make 5.1 dolby digital audio work in chromecast from exoplayer

I hope someone can help me with this problem. When I use the shakaplayer demo (https://v2-4-7-dot-shaka-player-demo.appspot.com/demo/#build=uncompiled), and in Configuration-> Preferred audio channel count: (I put the option in 6 channels) Dolby 5.1 sounds on the chromecast here is an example of my m3u8 files.

When I cast from exoplayer it only sounds 2.0 AAC, How can I make 5.1 sound sound on chromecast using exoplayer?

#EXTM3U
## Generated with https://github.com/google/shaka-packager version v2.3.0-5bf8ad5ed5-release

#EXT-X-MEDIA:TYPE=AUDIO,URI="audio-eng-2/main.m3u8",GROUP-ID="audio_aac",LANGUAGE="en",NAME="ENGLISH",AUTOSELECT=YES,CHANNELS="2"
#EXT-X-MEDIA:TYPE=AUDIO,URI="audio-spa-2/main.m3u8",GROUP-ID="audio_aac",LANGUAGE="es",NAME="SPANISH",DEFAULT=YES,AUTOSELECT=YES,CHANNELS="2"
#EXT-X-MEDIA:TYPE=AUDIO,URI="a-eng-ac3/main.m3u8",GROUP-ID="audio_ac3",LANGUAGE="en",NAME="ENGLISH-DD",AUTOSELECT=YES,CHANNELS="6"
#EXT-X-MEDIA:TYPE=AUDIO,URI="a-spa-ac3/main.m3u8",GROUP-ID="audio_ac3",LANGUAGE="es",NAME="SPANISH-DD",DEFAULT=YES,AUTOSELECT=YES,CHANNELS="6"

#EXT-X-STREAM-INF:BANDWIDTH=818330,AVERAGE-BANDWIDTH=739176,CODECS="avc1.64002a,mp4a.40.2",RESOLUTION=640x268,AUDIO="audio_aac"
h264_360p/main.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=5971603,AVERAGE-BANDWIDTH=5449558,CODECS="avc1.64002a,mp4a.40.2",RESOLUTION=1920x800,AUDIO="audio_aac"
h264_1080p/main.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=1226912,AVERAGE-BANDWIDTH=1106481,CODECS="avc1.64002a,mp4a.40.2",RESOLUTION=842x352,AUDIO="audio_aac"
h264_480p/main.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=3245473,AVERAGE-BANDWIDTH=2816564,CODECS="avc1.64002a,mp4a.40.2",RESOLUTION=1279x534,AUDIO="audio_aac"
h264_720p/main.m3u8

#EXT-X-STREAM-INF:BANDWIDTH=1063700,AVERAGE-BANDWIDTH=992710,CODECS="avc1.64002a,ac-3",RESOLUTION=640x268,AUDIO="audio_ac3"
h264_360p/main.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=6216973,AVERAGE-BANDWIDTH=5703092,CODECS="avc1.64002a,ac-3",RESOLUTION=1920x800,AUDIO="audio_ac3"
h264_1080p/main.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=1472282,AVERAGE-BANDWIDTH=1360015,CODECS="avc1.64002a,ac-3",RESOLUTION=842x352,AUDIO="audio_ac3"
h264_480p/main.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=3490843,AVERAGE-BANDWIDTH=3070098,CODECS="avc1.64002a,ac-3",RESOLUTION=1279x534,AUDIO="audio_ac3"
h264_720p/main.m3u8

#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=96463,AVERAGE-BANDWIDTH=23629,CODECS="avc1.64002a",RESOLUTION=640x268,URI="h264_360p/iframe.m3u8"
#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=576190,AVERAGE-BANDWIDTH=130909,CODECS="avc1.64002a",RESOLUTION=1920x800,URI="h264_1080p/iframe.m3u8"
#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=150798,AVERAGE-BANDWIDTH=35289,CODECS="avc1.64002a",RESOLUTION=842x352,URI="h264_480p/iframe.m3u8"
#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=344443,AVERAGE-BANDWIDTH=72033,CODECS="avc1.64002a",RESOLUTION=1279x534,URI="h264_720p/iframe.m3u8"

from How to make 5.1 dolby digital audio work in chromecast from exoplayer