Removed draggable style from URL bar (was causing maximize w/ double …

[bsclifton]

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

Removed draggable style from URL bar (was causing maximize w/ double click on Windows)

Fixes #4922

Auditors: @bbondy

Test plan:

1. Launch Brave on Windows and double click inside URL bar (ex: to left of
   lock icon or on the time loaded)
2. Window should no longer maximize.
3. Lock icon is still drag/droppable onto bookmarks toolbar, etc.

[bbondy]

++ thanks