[Material Icons] Icons look so small on extension icons

[ardacebi]

Describe the bug
Extension icons inside the admin/extensions page look so small because of the Material icon change.

To Reproduce
Steps to reproduce the behavior:

1. Go to admin panel
2. Click on extensions
3. See error

Expected behavior
Small icons should be shown small but icons on the extensions page should be shown big.

Current behavior
Small icons are OK, but big icons are not working.

Screenshots

Environment (please complete the following information):

• OS: macOS Mojave
• Browser: firefox