[Desktop] Brave Rewards in add widget menu jumps around when other widgets are shown/hidden

[srirambv]

Description

Brave Rewards in add widget menu jumps around when other widgets are shown/hidden

Steps to Reproduce

1. Install 1.13.16
2. Open dashboard settings and add/remove existing widgets
3. When one of the widget is added/removed Brave rewards widget moves to a different position and jumps back to its place

Actual result:

Expected result:

Widget card should retain its original position

Reproduces how often:

Easy

Brave version (brave://version info)

Brave	1.13.16 Chromium: 84.0.4147.89 (Official Build) nightly (64-bit)
Revision	19abfe7bcba9318a0b2a6bc6634a67fc834aa592-refs/branch-heads/4147@{# 852}
OS	Linux

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 dev channel? NA
• Can you reproduce this issue with the nightly channel? Yes

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:

cc: @karenkliu @petemill @jamesmudgett
@ryanml please add it to Crypto/Widgets project board if required.

[GeetaSarvadnya]

Verification passed on

Brave | 1.13.73 Chromium: 84.0.4147.125 (Official Build) dev (64-bit)
-- | --
Revision | d0784639447f2e10d32ebaf9861092b20cfde286-refs/branch-heads/4147@{#1059}
OS | Windows 10 OS Version 1903 (Build 18362.1016)

• Verified the STR from the description
• Encountered [Desktop] Customized Dashboard settings tool tip is shown outside the modal popup #10299

Verification passed on

Brave	1.13.77 Chromium: 85.0.4183.69 (Official Build) dev (64-bit)
Revision	4554ea1a1171bd8d06951a4b7d9336afe6c59967-refs/branch-heads/4183@{#1426}
OS	Ubuntu 18.04 LTS

• Verified the STR from the description

---

Verified passed with

Brave | 1.13.79 Chromium: 85.0.4183.69 (Official Build) dev (64-bit)
-- | --
Revision | 4554ea1a1171bd8d06951a4b7d9336afe6c59967-refs/branch-heads/4183@{#1426}
OS | macOS Version 10.14.6 (Build 18G3020)

• Verified the STR from the description