chore: handle list of objects (#659)

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# Fixes #

In case of list of objects, we need to serialize using objectToJson()
Preview changes - twilio/twilio-java#874

### Checklist
- [x] I acknowledge that all my contributions will be made under the
project's license
- [ ] Run `make test-docker`
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- [ ] Generate [twilio-go](https://github.com/twilio/twilio-go) from our
[OpenAPI specification](https://github.com/twilio/twilio-oai) using the
[build_twilio_go.py](./examples/build_twilio_go.py) using `python
examples/build_twilio_go.py path/to/twilio-oai/spec/yaml
path/to/twilio-go` and inspect the diff
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If you have questions, please create a GitHub Issue in this repository.

Author: tiwarishubham635

examples/java/src/main/java/com/twilio/rest/flexapi/v1/credential/NewCredentialsCreator.java

@@ -258,7 +258,7 @@ private void addPostParams(final Request request) {
         }
         if (testAnyArray != null) {
             for (Object prop : testAnyArray) {
-                request.addPostParam("TestAnyArray", prop.toString());
+                request.addPostParam("TestAnyArray", Converter.objectToJson(prop));
             }
 
         }

src/main/java/com/twilio/oai/api/JavaApiResourceBuilder.java

@@ -431,6 +431,8 @@ private void processDataTypesForParams(List<CodegenParameter> finalQueryParamLis
                 cp.vendorExtensions.put("x-is-other-data-type", true);
             } else if (cp.isArray && cp.baseType.equalsIgnoreCase(STRING)) {
                 cp.vendorExtensions.put("x-is-string-array", true);
+            } else if (cp.isArray && cp.items != null && cp.items.isAnyType) {
+                cp.vendorExtensions.put("x-is-anytype-array", true);
             }
 
         }

src/main/resources/twilio-java/postParams.mustache

@@ -29,9 +29,16 @@
             }
         {{/vendorExtensions.x-is-string-array}}
         {{^vendorExtensions.x-is-string-array}}
+        {{#vendorExtensions.x-is-anytype-array}}
+            for ({{baseType}} prop : {{paramName}}) {
+                request.addPostParam("{{baseName}}", Converter.objectToJson(prop));
+            }
+        {{/vendorExtensions.x-is-anytype-array}}
+        {{^vendorExtensions.x-is-anytype-array}}
             for ({{baseType}} prop : {{paramName}}) {
                 request.addPostParam("{{baseName}}", prop.toString());
             }
+        {{/vendorExtensions.x-is-anytype-array}}
         {{/vendorExtensions.x-is-string-array}}
         {{/isEnum}}
     {{/isArray}}