Populate fileType also when MQTT protocol is in use

[ileonovAmzn]

Currently in job_parser.c, fileType field from the job document is only parsed and populated into the AfrOtaJobDocumentFields_t struct if protocol value is not "MQTT": it is done in populateHttpStreamingFields().

In AWS IoT Core console, when creating an OTA job, fileType can be populated also when MQTT protocol is selected for the job.

We are using the Jobs-for-AWS-IoT-embedded-sdk library with a job over MQTT protocol and we would like to set fileType value in the job document to indicate to our OTA agent what type of content the job has.

I suggest to move fileType parsing code to populateCommonFields() from populateHttpStreamingFields().

[kstribrnAmzn]

Thanks for submitting the issue! This seems like a reasonable change. I'm reaching out to the jobs team to verify the filetype is always included for both MQTT and HTTP transmission.