[Desktop][CW] Backup seed words message should not block token list

[srirambv]

Description

Backup seed words message should not block token list

Steps to Reproduce

1. Load 0.1.66 component
2. Skip wallet back up process
3. Add a bunch of tokens
4. Scroll down, backup token message is blocking send token button

Actual result:

Expected result:

Should not have a fixed position but rather a relative position at the end of the page with scroll

Reproduces how often:

Easy.

Brave version (brave://version info)

Brave	1.13.75 Chromium: 85.0.4183.69 (Official Build) beta (64-bit)
Revision	4554ea1a1171bd8d06951a4b7d9336afe6c59967-refs/branch-heads/4183@{#1426}
OS	Linux
Component	0.1.66

Version/Channel Information:

• Can you reproduce this issue with the current release? NA
• Can you reproduce this issue with the beta channel? NA
• Can you reproduce this issue with the nightly channel? NA

Other Additional Information:

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

Miscellaneous Information:

This is an issue on MM as well. Would be a good upstream fix as polish/enhancement

[srirambv]

Moving out of 1.0.21 as this is just a suggestion and should not block the release

[srirambv]

Verification passed on

Brave	1.13.86 Chromium: 85.0.4183.102 (Official Build) (64-bit)
Revision	ffe848af6a5df4fa127e2929331116b7f9f1cb30-refs/branch-heads/4183@{#1770}
OS	Windows 10 OS Version 1809 (Build 17763.1457)
Component	0.1.75

• Verified backup seed words message is not blocking add token list
  

---

Verification passed on

Brave	1.15.46 Chromium: 85.0.4183.102 (Official Build) beta (64-bit)
Revision	ffe848af6a5df4fa127e2929331116b7f9f1cb30-refs/branch-heads/4183@{#1770}
OS	Linux
Component	0.1.75

• Verified backup seed words message is not blocking add token list
  

---

Verification passed on

Brave	1.16.7 Chromium: 85.0.4183.102 (Official Build) nightly (64-bit)
Revision	ffe848af6a5df4fa127e2929331116b7f9f1cb30-refs/branch-heads/4183@{#1770}
OS	macOS Version 10.15.5 (Build 19F101)
Component	0.1.75

• Verified backup seed words message is not blocking add token list