excluded list doesn't include 'on YouTube' or 'on Twitch' as appropriate

[LaurenWags]

Description

When viewing excluded list of sites, if you have a YouTube or Twitch channel excluded, the list does not contain 'on YouTube' or 'on Twitch' following the channel name. This is shown in the a-c list, tips list, and panel.

Steps to Reproduce

1. Watch a video on YouTube long enough for it to be added to auto contribute table.
2. Go to AC table and exclude channel.
3. Open list of excluded sites.

Actual result:

Expected result:

list includes 'on YouTube' or 'on Twitch' as appropriate.

Reproduces how often:

easily

Brave version (brave://version info)

Brave	0.67.72 Chromium: 75.0.3770.38 (Official Build) dev(64-bit)
Revision	3860105745f2b12537da9e9f048f14c3f52ba970-refs/branch-heads/3770@{#618}
OS	Mac OS X

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a
• Can you reproduce this issue with the beta channel? n/a
• Can you reproduce this issue with the dev channel? yes
• Can you reproduce this issue with the nightly channel? yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? n/a
• Does the issue resolve itself when disabling Brave Rewards? n/a
• Is the issue reproducible on the latest version of Chrome? n/a

Miscellaneous Information:

Should check Twitter as well once it's included in a-c.

[LaurenWags]

Verified passed with

Brave	0.69.119 Chromium: 76.0.3809.132 (Official Build) beta (64-bit)
Revision	fd1acc410994a7a68ac25bc77513d443f3130860-refs/branch-heads/3809@{#1035}
OS	Mac OS X

• Verified STR from description for YouTube, Twitch, Vimeo:
  

Verification passed on

Brave	0.69.121 Chromium: 76.0.3809.132 (Official Build) beta (64-bit)
Revision	fd1acc410994a7a68ac25bc77513d443f3130860-refs/branch-heads/3809@{#1035}
OS	Ubuntu 18.04 LTS

• Verified STR from description for YouTube, Twitch, Vimeo:
  
  

Verification passed on

Brave	0.69.121 Chromium: 76.0.3809.132 (Official Build) beta (64-bit)
Revision	fd1acc410994a7a68ac25bc77513d443f3130860-refs/branch-heads/3809@{#1035}
OS	Windows 10 OS Version 1803 (Build 17134.523)

• Verified STR from the description for YouTube, Twitch, Vimeo: