Take volume cap into account in CTS

Due to new regulations, music sent over a wired headset may be volume limited
until the user explicitly increases the limit, so CTS can't rely on being able
to set the volume to getStreamMaxVolume() in that case.
b/7198289

Change-Id: If4a8cd5778c083f704f448e071be53ccf9b93ef0
1 file changed