[tests] fix external commissioner building options (#5321)
[tests] fix external commissioner building options (#5321)

This commit aligns the external commissioner building options with OT
commissioner.
chshu/openthread,chshu/openthread,openthread/openthread,bukepo/openthread,chshu/openthread,openthread/openthread,chshu/openthread,jwhui/openthread,abtink/openthread,chshu/openthread,srickardti/openthread,bukepo/openthread,srickardti/openthread,abtink/openthread,jwhui/openthread,abtink/openthread,abtink/openthread,jwhui/openthread,bukepo/openthread,jwhui/openthread,openthread/openthread,srickardti/openthread,srickardti/openthread,chshu/openthread,bukepo/openthread,openthread/openthread