Documents cannot be downloaded correctly if file size is less than 1024kb

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.1.0 Beta 2, 7.1.X, Master
• Component/s: DM
• Labels: None
• Fix Priority: 5
• OS:
  Windows 10
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/58856

Steps to reproduce:

1. Add a bunch of documents with a variety of file extensions in Documents and Media
2. Select any combination of documents (<1024kb) and click on the download icon
3. Assert a Liferay.zip is downloaded
4. Open up Liferay.zip

Expected result:
The files that were selected appear in the zip.

Actual result:
The zip file is empty.

If total file size of the documents is >1024kb, all the selected files appear in the zip.

There are no issues when downloading a document file using the standard download link.

Reproduced on:
Windows
Tomcat 9.0.6 + MySQL 5.7.
Portal master GIT ID: 5e54567774d86a9079b6040fac0b75dec7dd9146