update java samples

samples/client/petstore/java/apache-httpclient/api/openapi.yaml

@@ -158,7 +158,7 @@ paths:
       tags:
       - pet
       x-webclient-blocking: true
-      x-accepts: application/json
+      x-accepts: "application/json,application/xml"
   /pet/findByTags:
     get:
       deprecated: true
@@ -203,7 +203,7 @@ paths:
       tags:
       - pet
       x-webclient-blocking: true
-      x-accepts: application/json
+      x-accepts: "application/json,application/xml"
   /pet/{petId}:
     delete:
       description: ""
@@ -271,7 +271,7 @@ paths:
       tags:
       - pet
       x-webclient-blocking: true
-      x-accepts: application/json
+      x-accepts: "application/json,application/xml"
     post:
       description: ""
       operationId: updatePetWithForm
@@ -387,7 +387,7 @@ paths:
       tags:
       - store
       x-content-type: application/json
-      x-accepts: application/json
+      x-accepts: "application/json,application/xml"
   /store/order/{order_id}:
     delete:
       description: For valid response try integer IDs with value < 1000. Anything
@@ -444,7 +444,7 @@ paths:
       summary: Find purchase order by ID
       tags:
       - store
-      x-accepts: application/json
+      x-accepts: "application/json,application/xml"
   /user:
     post:
       description: This can only be done by the logged in user.
@@ -543,7 +543,7 @@ paths:
       summary: Logs user into the system
       tags:
       - user
-      x-accepts: application/json
+      x-accepts: "application/json,application/xml"
   /user/logout:
     get:
       description: ""
@@ -606,7 +606,7 @@ paths:
       summary: Get user by user name
       tags:
       - user
-      x-accepts: application/json
+      x-accepts: "application/json,application/xml"
     put:
       description: This can only be done by the logged in user.
       operationId: updateUser