The documentation for requiredScripts states that the value for Google Maps is:
Code:
requiredScripts:{
    '//maps.googleapis.com/maps/api/js?key={key}' 
}
and that a mashup should look like:
Code:
"mashup": {
     "map": {  // the xtype
        "key": "[GOOGLE_MAPS_KEY]"
     }
Code:
}
This is INCORRECT. The requiredScripts is:
Code:
requiredScripts:{
    '//maps.googleapis.com/maps/api/js{options}' 
}
and so the mashup should look like:
Code:
"mashup": {
    "map": {  // the xtype
        "options": "?key=[GOOGLE_MAPS_KEY]"
     } 
}