fixed multipart file for image upload in swagger

application/src/main/java/org/thingsboard/server/controller/ImageController.java

@@ -25,6 +25,7 @@ import org.springframework.core.io.ByteArrayResource;
 import org.springframework.http.CacheControl;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.DeleteMapping;
@@ -93,7 +94,7 @@ public class ImageController extends BaseController {
     private static final String IMAGE_KEY_PARAM_DESCRIPTION = "Image resource key, for example thermostats_dashboard_background.jpeg";
 
     @PreAuthorize("hasAnyAuthority('SYS_ADMIN', 'TENANT_ADMIN')")
-    @PostMapping("/api/image")
+    @PostMapping(value = "/api/image", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
     public TbResourceInfo uploadImage(@RequestPart MultipartFile file,
                                       @RequestPart(required = false) String title) throws Exception {
         SecurityUser user = getCurrentUser();