Issue Summary

Get content rest api doesn't return property value. 

Steps to Reproduce

1. Go to confluence site, Click on create button to create page in draft mode. Note down the content id from url.  
2. Use postman collection or any similar tool to call "Create content property" api using content id that we got from above step. 
3. Call "Get Content Properties" api to confirm the property key and value. 
4. Call "Get Content" with `expand=metadata.properties` and you will see only keys with blank value. 
   1. API: protocol://host/{{basePath}}api/content/124256257?expand=metadata.properties

Expected Results

Expected key and value of properties in response.

Actual Results

Workaround

Client can use "Get content properties" to get property key and value.