IMO - comet is not suitable for consumption by low power devices on 4g...
This rest api you are consuming is not ready for mobile until it upgrades with an internal proxy/gateway to reach out on PUSH protocol to IOS/Android clients that prefer event notification via another API/ protocol that is more suitable than Comet.
If you must consume the api and reach android at the same time then consider building a proxy for your Android users that will convert the Comet-calls to android push messages.
You might look at something like Parse.com because they have great Native REST and Push for the android side. ie it would not be a big deal to proxy on a Heroko/AWS node and then send native android push to your clients.
--EDIT android code