Implement a more robust mechanism to determine whether a report has been successfully sent by the server

In some cases (in Zambia) when a phone is not properly configured to transmit data, the operator returns a HTTP_NO_CONTENT (204) message. The DHIS2 also returns a HTTP_NO_CONTENT (204) message when a report has been successfully received by the server. This mechanism is not robust enough, as many reports here have gone missing because of this. We need a more robust mechanism (perhaps a checksum or other acknowledgment from the server) that the report has been successfully received, utilizing something other than a 204 status code.