Resolve "New File page file name field unclickable"

What does this MR do?

Issue: #196135 (closed)

In mobile view, the file name field on the "New File" page in the repo is unclickable. This MR fixes it.

Screenshots

There is no visible change in the UI. The file name filed is clickable now.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content