renamed extension property name on codegen content class.

Author: HugoMario

modules/swagger-codegen/src/main/java/io/swagger/codegen/v3/CodegenContent.java

@@ -5,7 +5,7 @@
 import java.util.List;
 import java.util.Map;
 
-public class CodegenContent implements VendorExtendable {
+public class CodegenContent {
 
     private String contentType;
 
@@ -17,13 +17,13 @@ public CodegenContent(String contentType) {
     }
 
     private List<CodegenParameter> parameters = new ArrayList<CodegenParameter>();
-    private Map<String, Object> vendorExtensions = new HashMap<>();
+    private Map<String, Object> contentExtensions = new HashMap<>();
 
     public boolean getIsForm() {
-        if (vendorExtensions.get(CodegenConstants.IS_FORM_EXT_NAME) == null) {
+        if (contentExtensions.get(CodegenConstants.IS_FORM_EXT_NAME) == null) {
             return Boolean.FALSE;
         }
-        return Boolean.parseBoolean(vendorExtensions.get(CodegenConstants.IS_FORM_EXT_NAME).toString());
+        return Boolean.parseBoolean(contentExtensions.get(CodegenConstants.IS_FORM_EXT_NAME).toString());
     }
 
     public List<CodegenParameter> getParameters() {
@@ -38,8 +38,7 @@ public void setContentType(String contentType) {
         this.contentType = contentType;
     }
 
-    @Override
-    public Map<String, Object> getVendorExtensions() {
-        return vendorExtensions;
+    public Map<String, Object> getContentExtensions() {
+        return contentExtensions;
     }
 }