Gear Icon for UIO+ browser action is small

[jobara]

Describe the bug

Some users provided feedback that the gear icon used for the UIO+ browser action is too small and hard to see.

https://developer.chrome.com/extensions/browserAction

Originally filed at GPII-4240

To reproduce

Steps to reproduce the behavior:

1. Install and enable UIO+
   Notice that the browser action icon, blue gears, are small and may be hard to see.

Expected behavior

The icon should be easily identified and identifiable. That is, it should be clear to see and understood that it is for UIO+

[jobara]

In looking at the UIO+ icon used for the extension page, it is a circle with the logo inside. The browser action icon is better served with a square icon (see: https://developer.chrome.com/extensions/browserAction ). Additionally the browser action is only 16dip which you could think of as 16px. Because of the size restriction we should try to make the icon itself fill as much of that room as possible.