Thanks for posting your solution. We added the oauth module in the PHP folder. Did you enabled it in the PHP configuration right? It is only necessary to edit the /opt/bitnami/php/etc/php.ini file and uncomment the ";extension=oauth.so" line. Then restart Apache server:
/opt/bitnami/ctlscript.sh restart apache
Regarding the Magento application itself not sure if it also require changes. Could you check that you have OAuth enabled?