tests: Use command line to enable bitrate adaptation
tests: Use command line to enable bitrate adaptation

Closes #507.

alessandrod/openwebrtc,philn/openwebrtc,philn/openwebrtc,alessandrod/openwebrtc,multipath-rtp/openwebrtc,stefhak/openwebrtc,pererikb/openwebrtc,shoreflyer/openwebrtc,stefhak/openwebrtc,shoreflyer/openwebrtc,alessandrod/openwebrtc,multipath-rtp/openwebrtc,shoreflyer/openwebrtc,danielwegener/openwebrtc,EricssonResearch/openwebrtc,philn/openwebrtc,multipath-rtp/openwebrtc,adozenlines/openwebrtc,EricssonResearch/openwebrtc,adozenlines/openwebrtc,EricssonResearch/openwebrtc,shoreflyer/openwebrtc,adozenlines/openwebrtc,danielwegener/openwebrtc,pererikb/openwebrtc,shoreflyer/openwebrtc,danielwegener/openwebrtc,multipath-rtp/openwebrtc,stefhak/openwebrtc,philn/openwebrtc,danielwegener/openwebrtc,philn/openwebrtc,alessandrod/openwebrtc,alessandrod/openwebrtc,stefhak/openwebrtc,danielwegener/openwebrtc,multipath-rtp/openwebrtc,stefhak/openwebrtc,danielwegener/openwebrtc,shoreflyer/openwebrtc,EricssonResearch/openwebrtc,pererikb/openwebrtc,pererikb/openwebrtc,pererikb/openwebrtc,alessandrod/openwebrtc,multipath-rtp/openwebrtc,multipath-rtp/openwebrtc,pererikb/openwebrtc,EricssonResearch/openwebrtc,adozenlines/openwebrtc,shoreflyer/openwebrtc,philn/openwebrtc,EricssonResearch/openwebrtc,EricssonResearch/openwebrtc,pererikb/openwebrtc,adozenlines/openwebrtc,stefhak/openwebrtc,philn/openwebrtc,adozenlines/openwebrtc