"edit_entry.jsp is not a valid include" ERROR message appears in logs when flagging a blogs entry as inappropriate

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X EE, Master
• Fix Version/s: 7.0.0 DXP FP14, 7.0.0 DXP SP3, 7.0.3 CE GA4, 7.0.X EE, 7.1.X, Master
• Component/s: ~ [Archived] Collaboration
• Labels:
  • liferay-digital-enterprise-70-sp3
  • liferay-fixpack-de-14-7010
• Branch Version/s:
  7.0.x
• Backported to Branch:
  Committed
• Story Points: 1
• Fix Priority: 2
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/48590

Description
Whenever a user flags anything as inappropriate (such as a Blogs Entry or Message Boards Thread), the following error message appears in the logs:

ERROR [http-nio-8080-exec-10][MVCPortlet:574] edit_entry.jsp is not a valid include

This happens as a result of this line of code. "edit_entry.jsp" should begin with a forward slash, but it does not.

Steps to Reproduce
1. Start up Liferay and log in as the admin user.
2. Add a Blogs portlet to a page.
3. Add a Blogs entry.
4. Add a new user.
5. Log out as the admin user and log in as the new user.
6. Visit the Blogs entry that was added in step 3.
7. Flag the content as inappropriate and click Save.
8. Observe the logs.

Expected result: No error messages would be displayed in the logs.
Actual result: An ERROR [http-nio-8080-exec-10][MVCPortlet:574] edit_entry.jsp is not a valid include message is displayed in the logs.

Reproduced in
master (c0abeac6506e0970d0f4779f7e9ba2ce5516322e)
Cannot test in ee-7.0.x until BPR-8311 is committed. However, I reproduced this issue in my local branch of ee-7.0.x with BPR-8311 merged into it (based on 9181eb20e655278d710785e9c86b0d8a5e1e2a66)