In a non-connected state, the link brave://rewards#monthly-statements opens up the monthly statement which doesn't exist

[GeetaSarvadnya]

Description

Found while testing #16628
In a non-connected state, the link brave://rewards#monthly-statements opens up the monthly statement which doesn't exist

Steps to Reproduce

1. Clean profile 1.52.x
2. Enable rewards and don't connect any custodian
3. Open a new tab and enter brave://rewards#monthly-statements
4. Monthly statement modal popup is opened

Actual result:

In a non-connected state, the link brave://rewards#monthly-statements opens up the monthly statement which doesn't exist

Expected result:

Monthly statement modal popup should not open as it doesn't exist in a non-connected state

Reproduces how often:

Easy

Brave version (brave://version info)

Brave	1.53.76 Chromium: 114.0.5735.90 (Official Build) beta (64-bit)
Revision	386bc09e8f4f2e025eddae123f36f6263096ae49-refs/branch-heads/5735@{#1052}
OS	Windows 10 Version 22H2 (Build 19045.2965)

Version/Channel Information:

• Can you reproduce this issue with the current release? NA
• Can you reproduce this issue with the beta channel? Yes
• 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: @brave/qa-team @mkarolin @Miyayes

[LaurenWags]

Verified with

Brave | 1.57.6 Chromium: 115.0.5790.75 (Official Build) beta (x86_64)
-- | --
Revision | 3433e4d513e8454ba0243deea3d53693661dc0c3-refs/branch-heads/5790@{#1430}
OS | macOS Version 13.4.1 (Build 22F82)

Verified STR from description.
Confirmed monthly statement was not opened when it does not exist.