fix: pass Content-Type header with its specific URI (#661)

CHANGELOG.md

@@ -26,6 +26,7 @@ the detailed section referring to by linking pull requests or issues.
 - Asset: Fix double encoding of query params by disallowing '&' and '=' chars in
   form field and sending them unencoded
 - Fixed an issue that prevented custom headers from being included in HTTP Data Transfers
+- Fix `Content-Type` header being ignored by backend for transfers
 
 #### Deployment Migration Notes
 

src/app/core/services/http-params-mapper.service.ts

@@ -75,10 +75,13 @@ export class HttpRequestParamsMapper {
       ),
       [DataAddressProperty.proxyBody]: bool(httpRequestParams.proxyBody),
       [DataAddressProperty.queryParams]: httpRequestParams.queryParams,
-      ...mapKeys(
-        httpRequestParams.headers,
-        (k) => `${DataAddressProperty.header}:${k}`,
-      ),
+      ...mapKeys(httpRequestParams.headers, (k) => {
+        if (k.toLowerCase() === 'content-type') {
+          // this is required because the EDC sends the Content-Type header if and only if provided using the special field "contentType"
+          return DataAddressProperty.contentType;
+        }
+        return `${DataAddressProperty.header}:${k}`;
+      }),
     };
     return removeNullValues(props);
   }