Wrong error message from Multiple File Uploader when request is killed by external server

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.2.X, Master
• Fix Version/s: 7.2.10 DXP FP15, 7.2.X, 7.3.10.3 DXP SP3, 7.3.X, 7.4.2 CE GA3, 7.4.13 DXP GA1, Master
• Component/s: Documents & Media
• Labels:
  • ee-ts
  • liferay-dxp-73-sp3
  • liferay-fix-pack-dxp-3-7310
  • liferay-fixpack-dxp-15-7210
  • liferay-fixpack-dxp-3-7310
• Branch Version/s:
  7.3.x, 7.2.x
• Backported to Branch:
  Committed
• Story Points: 1
• Fix Priority: 2
• Git Pull Request: https://github.com/liferay-lima/liferay-portal/pull/1971
• QA Test Name:
  • dont-test-again

Description
When an unexpected error occurs during the file upload process on the Upload Multiple File Entries page, Liferay displays the wrong error message in the UI. Rather than displaying the string "an-unexpected-error-occurred-while-uploading-your-file," Liferay displays the following: "an-unexpected-error-occurred-while-deleting-the-file."

Steps to Reproduce
1. Set up an Apache web server in front of Liferay
2. Start up Liferay and access Liferay through the web server URL
3. Navigate to Documents and Media and add a document using the Multiple File Uploader
4. Drag and drop a large file (i.e. 4GB), and then click Publish
5. While the document is publishing, stop the Apache web server

Expected Result: User sees an error in the UI stating that an unexpected error occurred while uploading the file.
Actual Result: User sees this error in the UI stating that an unexpected error occurred while deleting the file.

Reproduced in
master: 9d0da4ae005b1b139c8059947c32ff873077fa88
7.2.x: cac425dbb90de25641023cd7765c74e4df914953