improve the "BETA" tag under brave://sync

[kjozwiak]

Description

We decided to add a Beta string into brave://sync but due to time constraints and limited resources as folks were on PTO, we added some text rather than making it look like it did under muon. The current fix looks a bit sloppy and needs to be improved.

Steps to Reproduce

1. open 0.59.30 Chromium: 72.0.3626.71
2. visit brave://sync

Actual result:

Expected result:

The above or something similar that looks better.

Reproduces how often:

100% reproducible using the above STR.

Brave version (brave://version info)

Brave	0.59.30 Chromium: 72.0.3626.71 (Official Build) (64-bit)
Revision	f52ccad2a6a3c65fc9e0c591a517ceab1198dac0-refs/branch-heads/3626@{#763}
OS	Mac OS X

Reproducible on current release:

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

Reproducible on all channels that have Sync enabled by default

Website problems only:

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

Additional Information

CCing @rebron & @bsclifton

[rossmoody]

After talking with @rebron yesterday in the office, the consensus is to not add the beta label to this and the change that created the above (beta) string has been reverted. So it will just read Sync Setup.