The order doesn't matter, but I usually put the mapping stuff after support, but before text field character limit. It'll look like this...
"support": {
"email": "support@getodk.org"
},
"maps": [ {
"name": "satellite",
"tiles": "GOOGLE_SATELLITE"
} ],
"google": {
"api key": "my-google-api"
},
"text field character limit": 1000000,
"exclude non-relevant": true