Tips panel doesn't show 'on YouTube' text as Auto Contribute table does

[LaurenWags]

Description

Auto Contribute panel adds 'on YouTube' text for when a content creator is a YouTube channel or 'on Twitch' if content creator is a Twitch channel. If you tip a YouTube channel, the Tips panel doesn't display 'on YouTube' text (unable to check Twitch due to #1814).

Steps to Reproduce

1. Enable Rewards and accept a grant to fund your wallet (I was on staging).
2. Navigate to a YouTube video. Watch for a bit so it gets added to Auto Contribute table.
3. Click on the BAT logo.
4. Click on Send a Tip button on panel.
5. Choose an amount and send.
6. Navigate to Rewards page.

Actual result:

Auto Contribute table shows 'on YouTube' text, but Tips does not.

Expected result:

Both places should show 'on YouTube' text.

Reproduces how often:

easy

Brave version (brave://version info)

Brave	0.56.8 Chromium: 70.0.3538.77 (Official Build) (64-bit)
Revision	0f6ce0b0cd63a12cb4eccea3637b1bc9a29148d9-refs/branch-heads/3538@{#1039}
OS	Mac OS X

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds? yes

Website problems only:

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

Additional Information

Should be checked for Twitch when #1814 is resolved.

[LaurenWags]

Verified passed on

Brave	0.58.11 Chromium: 71.0.3578.80 (Official Build) beta(64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Mac OS X

• Verified STR
  

Verification passed on

Brave	0.58.11 Chromium: 71.0.3578.80 (Official Build) beta (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Windows

• Verified the STR mentioned in description
  

Verification passed on

Brave	0.58.11 Chromium: 71.0.3578.80 (Official Build) beta (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Linux