Fix send_activation_email registation api parameters
Fix send_activation_email registation api parameters

Some parameters were passed to the core code as string representations
of True and False, causing a boolean comparison to "False"

This fix has not been locally tested. We'll test it on Tahoe staging

Ticket RED-113

appsembler/edx-platform,appsembler/edx-platform,appsembler/edx-platform,appsembler/edx-platform