Fix unchecked conversion

Created by: tjzeeman

Update restttemplate and webclient templates to use <>-operator. Also update samples.

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• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
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  ./mvnw clean package 
  ./bin/generate-samples.sh
  ./bin/utils/export_docs_generators.sh

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modules/openapi-generator/src/main/resources/Java/libraries/resttemplate/ApiClient.mustache

@@ -671,7 +671,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
     public <T> ResponseEntity<T> invokeAPI(String path, HttpMethod method, Map<String, Object> pathParams, MultiValueMap<String, String> queryParams, Object body, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams, MultiValueMap<String, Object> formParams, List<MediaType> accept, MediaType contentType, String[] authNames, ParameterizedTypeReference<T> returnType) throws RestClientException {
         updateParamsForAuth(authNames, queryParams, headerParams, cookieParams);
 
-   	    Map<String,Object> uriParams = new HashMap();
+   	    Map<String,Object> uriParams = new HashMap<>();
         uriParams.putAll(pathParams);
 
         String finalUri = path;

modules/openapi-generator/src/main/resources/Java/libraries/webclient/ApiClient.mustache

@@ -654,7 +654,7 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
         final UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(basePath).path(path);
 
         String finalUri = builder.build(false).toUriString();
-        Map<String, Object> uriParams = new HashMap();
+        Map<String, Object> uriParams = new HashMap<>();
         uriParams.putAll(pathParams);
 
         if (queryParams != null && !queryParams.isEmpty()) {

samples/client/petstore/java/resttemplate/src/main/java/org/openapitools/client/ApiClient.java

@@ -622,7 +622,7 @@ public class ApiClient extends JavaTimeFormatter {
     public <T> ResponseEntity<T> invokeAPI(String path, HttpMethod method, Map<String, Object> pathParams, MultiValueMap<String, String> queryParams, Object body, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams, MultiValueMap<String, Object> formParams, List<MediaType> accept, MediaType contentType, String[] authNames, ParameterizedTypeReference<T> returnType) throws RestClientException {
         updateParamsForAuth(authNames, queryParams, headerParams, cookieParams);
 
-   	    Map<String,Object> uriParams = new HashMap();
+   	    Map<String,Object> uriParams = new HashMap<>();
         uriParams.putAll(pathParams);
 
         String finalUri = path;

samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/ApiClient.java

@@ -627,7 +627,7 @@ public class ApiClient extends JavaTimeFormatter {
     public <T> ResponseEntity<T> invokeAPI(String path, HttpMethod method, Map<String, Object> pathParams, MultiValueMap<String, String> queryParams, Object body, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams, MultiValueMap<String, Object> formParams, List<MediaType> accept, MediaType contentType, String[] authNames, ParameterizedTypeReference<T> returnType) throws RestClientException {
         updateParamsForAuth(authNames, queryParams, headerParams, cookieParams);
 
-   	    Map<String,Object> uriParams = new HashMap();
+   	    Map<String,Object> uriParams = new HashMap<>();
         uriParams.putAll(pathParams);
 
         String finalUri = path;

samples/client/petstore/java/webclient/src/main/java/org/openapitools/client/ApiClient.java

@@ -641,7 +641,7 @@ public class ApiClient extends JavaTimeFormatter {
         final UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(basePath).path(path);
 
         String finalUri = builder.build(false).toUriString();
-        Map<String, Object> uriParams = new HashMap();
+        Map<String, Object> uriParams = new HashMap<>();
         uriParams.putAll(pathParams);
 
         if (queryParams != null && !queryParams.isEmpty()) {