Pasting text with leading whitespace in code snippet macro loses whitespace

Issue Summary

When you paste text that has leading whitespace into a code snippet macro, the whitespace is removed.

Steps to Reproduce

1. Open Confluence and create or edit a page. Add the Code snippet macro.
2. Write a couple of sentences on one line. (e.g. This is a test. Line 1)
3. Copy the text, but start with the whitespace (e.g. '_Line 1')
4. Paste the text in the code snippet on the next line. 

Expected Results

The whitespace should be included in the pasted text.

Actual Results

The whitespace is lost:

Workaround

Currently, there is no known workaround for this behavior. A workaround will be added here when available