Downvotes fail to redeem for ad confirmations

[Uni-verse]

Description:

Downvotes fail to redeem for ad confirmations, not a regression

Steps to Reproduce

1. Install 1.50.x or 1.49.1 dev channel build
2. Enable verbose logging (/brave/=5) in debug settings
3. Enable rewards
4. When ad notification is shown, swipe to left to remove (should see thumbs down)
5. Confirm view, click, dismiss, downvote ad nconfirmation is logged (console.app)
6. Observe whether downvote confirmation is redeemed

Actual result:

Expected result:

Should be redeemed

Reproduces how often: [Easily reproduced, Intermittent Issue]

Easily reproduced

Brave Version: 1.50 (23.4.27.16)

• Can you reproduce this issue with the most recent build from TestFlight? Yes
• Can you reproduce this issue with the previous version of the current build from TestFlight? Yes
• Can you reproduce this issue with the current build from AppStore? Yes

Device details:

Reproducible on 1.49.1.x
Reproducible on 1.50.x

[tmancey]

@Uni-verse could you please set the logging level to 6, and if possible send the log as a text file? Thanks

[btlechowski]

Not reproducible on desktop

Brave	1.52.86 Chromium: 113.0.5672.77 (Official Build) beta (64-bit)
Revision	c4236862955e005c2187105415ac4a2ecf86dff1-refs/branch-heads/5672_62@{#3}
OS	Ubuntu 18.04 LTS

[2796:2796:0511/122650.153867:VERBOSE1:redeem_opted_in_confirmation.cc(363)] Successfully redeemed opted-in downvote confirmation for ad_notification with transaction id 9d8f453a-1135-4d77-b67e-7f88b0d2cb3f and creative instance id 4cda3ae7-1f70-4bca-b361-ca01d6a8f1ed

[tmancey]

cc @tackley fix for 404 not found

[Uni-verse]

Verified on iPhone X running iOS 16.5.1 using version 1.53 (23.7.6.16)

Using STR in #7365 (comment)

• Ensured that downvotes are successfully redeemed for ad notifications