Blog full content display template doesn't display the subtitle

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X
• Fix Version/s: 7.0.0 DXP FP80, 7.0.10.11 DXP SP11, 7.0.X
• Component/s: Blogs
• Labels:
  • ee-ts
  • liferay-dxp-70-sp11
  • liferay-fixpack-de-80-7010
• Fix Priority: 2
• Git Pull Request: https://github.com/liferay/liferay-portal-ee/pull/13765

Description:
In Liferay DXP 7.0, the full content template doesn't display the subtitle of a blog. In 7.1, the subtitle shows when taking the same steps.

Steps to Reproduce:
1) Startup Liferay 7.0 and add a blog, with a title, subtitle and content 
2) Add a blog portlet to a page 
3) Configure the blog display template to show full content (blog portlet edit menu (three dots) > configurations > select full content (shown in .gif) > save
4) note subtitle missing 
5) Do the same with 7.1, note subtitle no longer missing

Expected Behavior: as shown in 7.1, setting the display template to full content would display the subtitle of a blog.

Actual Behavior: the subtitle is not shown

Reproduced: 
7.0.x: yes, 9db083d4213269e8c358f01f395b54c7d3e42bd1
Master: no, 8d53209073084511079c86e46929ec591677533e