[Desktop] Rewards tour does not have enough margin in rewards panel

[zenparsing]

Description

The rewards tour, when displayed in the rewards panel when there are no panel notifications, does not have quite enough margin on the top and bottom.

[stephendonner]

Verified FIXED using 1.21.44

Brave	1.21.44 Chromium: 88.0.4324.146 (Official Build) beta (x86_64)
Revision	406dc88511162d6598242f2c709be1414a042fb0-refs/branch-heads/4324@{#2088}
OS	macOS Version 11.2 (Build 20D64)

Followed the testplan from brave/brave-core#7677, and additionally resized the browser's viewport to constrain the panel flyout, which still enforced its margin padding nicely (2nd screenshot).

screenshots:

---

Verification passed on

Brave	1.20.104 Chromium: 88.0.4324.152 (Official Build) (64-bit)
Revision	6579930fc53b4dc589c042bec9d0a3778326974d-refs/branch-heads/4324@{#2106}
OS	Ubuntu 18.04 LTS

Verified the testplan from brave/brave-core#7677, and additionally resized the browser's viewport to constrain the panel flyout, which still enforced its margin padding nicely (2nd screenshot).

screenshots:

---

Verified passed with

Brave	1.21.59 Chromium: 88.0.4324.182 (Official Build) beta (64-bit)
Revision	73ee5087001dcef33047c4ed650471b225dd8caf-refs/branch-heads/4324@{#2202}
OS	Windows 10 OS Version 1909 (Build 18363.1256)

Verified test plan from brave/brave-core#7677.

Confirmed margins exist.

Example	Example