Shields should be disabled for magnet links

[stephendonner]

Description

Shields should be disabled for magnet links

Steps to Reproduce

1. install 1.39.33
2. launch Brave
3. load https://webtorrent.io/free-torrents
4. click on (magnet link) for any file (such as magnet:?xt=urn:btih:dd8255ecdc7ca55fb0bbf81323d87062db1f6d1c&dn=Big+Buck+Bunny&tr=udp%3A%2F%2Fexplodie.org%3A6969&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Ftracker.empire-js.us%3A1337&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337&tr=wss%3A%2F%2Ftracker.btorrent.xyz&tr=wss%3A%2F%2Ftracker.fastcast.nz&tr=wss%3A%2F%2Ftracker.openwebtorrent.com&ws=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2F&xs=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2Fbig-buck-bunny.torrent for Big Buck Bunny)
5. reload the page (to work around a long-standing issue)
6. examine/click on the Shields icon

Actual result:

It appears toggleable, but doesn't really do anything, nor correctly reflect its state.

Expected result:

Shields should be disabled (if we are looking for parity with current release).

Reproduces how often:

100%

Brave version (brave://version info)

Brave	1.39.73 Chromium: 101.0.4951.34 (Official Build) nightly (x86_64)
Revision	8f93af5d759634c5256b65997dedd138ed60992f-refs/branch-heads/4951@{#710}
OS	macOS Version 11.6.5 (Build 20G527)

Version/Channel Information:

• Can you reproduce this issue with the current release? no
• Can you reproduce this issue with the beta channel? yes
• Can you reproduce this issue with the nightly channel? yes

cc @nullhook @rebron @GeetaSarvadnya @MadhaviSeelam

[rebron]

Closed with brave/brave-core#13209

[stephendonner]

Verified PASSED using

Brave	1.41.47 Chromium: 102.0.5005.78 (Official Build) nightly (x86_64)
Revision	df6dbb5a9fd82af3f567198af2eb5fb4876ef99c-refs/branch-heads/5005_59@{#3}
OS	macOS Version 12.5 (Build 21G5037d)

Steps

1. installed 1.41.47
2. launched Brave
3. loaded `https://webtorrent.io/free-torrents
4. click on (magnet link) for any file (such as magnet:?xt=urn:btih:dd8255ecdc7ca55fb0bbf81323d87062db1f6d1c&dn=Big+Buck+Bunny&tr=udp%3A%2F%2Fexplodie.org%3A6969&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Ftracker.empire-js.us%3A1337&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337&tr=wss%3A%2F%2Ftracker.btorrent.xyz&tr=wss%3A%2F%2Ftracker.fastcast.nz&tr=wss%3A%2F%2Ftracker.openwebtorrent.com&ws=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2F&xs=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2Fbig-buck-bunny.torrent` for Big Buck Bunny)
   reload the page (to work around a long-standing issue)
   examine/click on the Shields icon

Confirmed the Shields icon is:

1. default disabled when on a magnet URI
2. not enableable