Disable subtitles on Chromecast

When I tell Google assistant “play (name of show) from Hulu” it has the Chromecast turn on the TV and the show plays. This is great except it ALWAYS turns on subtitles. I’m thinking a solution is have home assistant automatically turn them back off. I tried the following automation but Google says “sorry I can’t do that” even though if I verbally say the exact same words (“Turn off bedroom TV subtitles”) it will work.

alias: Bedroom TV Auto-Off Subtitles
description: ""
trigger:
  - platform: state
    entity_id:
      - media_player.lg_tv
    from: "off"
    for:
      hours: 0
      minutes: 0
      seconds: 15
condition: []
action:
  - service: google_assistant_sdk.send_text_command
    data:
      media_player: media_player.googlehome4588
      command: Activate "Turn off bedroom TV subtitles" automation

Is there a trick to make the google_assistant_sdk work for this or better yet a way to use the cast integration directly to do this?