[Android] Add QR code scanner to address bar

[timchilds]

Summary
A QR code scanner is already available in the iOS app. We should add the same feature to Android to be consistent.

Requirements

• When the URL bar is tapped, display a QR icon in the address bar (to the left of voice search icon).
• On tap, opens a QR scanner in modal (same modal stye as tab groups?)
• On successful scan, opens website.
• Include back icon for user to back out of the QR scanner (see mockup).
• Copy: same as iOS (see mockup).

Mockup

[aman-m1]

Can we have the ability to scan QR code from a file (image) as well that can be picked from device?

[Uni-verse]

Verified using the following build(s):

Brave	1.45.106 Chromium: 107.0.5304.36 (Official Build) (64-bit) 
Revision	2f9c7a5a1fe357d87e9bc07c65cca9136b3651c5-refs/branch-heads/5304@{#671}
OS	Android 12; Build/SP1A.210812.016

• Verified QR code scanner icon is in the url bar when curser is present
• Verified tapping code scanner will launch the modal
• Verified webpage is loaded on successful scan
• Verified tapper the back arrow will close the QR code scanner modal
• Verified scanning webpage url will launch the webpage or populate in the url box
• Verified scanning QR code for crypto wallet address populates the value in the url box
• Verified copy is same as on iOS

Example	Example	Example