getMaxBitrate() {
    const key = shaka.util.CmsdManager.KEYS_.MAX_SUGGESTED_BITRATE;
    if (!this.config_.enabled || !this.config_.applyMaximumSuggestedBitrate ||
        !this.dynamicParams_ || !this.dynamicParams_.has(key)) {
      return null;
    }
    return /** @type {number} */(this.dynamicParams_.get(key)) * 1000;
  }
Returns the max bitrate in bits per second. If there is no max bitrate or
it's not enabled, it returns null.

@return {?number}
@export