Android Fix NTP SI, imagecredit cutoff (uplift to 1.37.x)

[brave-builds]

Uplift of #12711
Resolves brave/brave-browser#21736

Pre-approval checklist:

• You have tested your change on Nightly.
• This contains text which needs to be translated.
  • There are more than 7 days before the release.
  • I've notified folks in #l10n on Slack that translations are needed.
• The PR milestones match the branch they are landing to.

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• You have checked CI and the builds, lint, and tests all pass or are not related to your PR.

Post-merge checklist:

• The associated issue milestone is set to the smallest version that the changes is landed on.

[kjozwiak]

Windows failed test-browser due to RequestAdsEnabledApiTestEnabled.RewardsEnablePopupAccepted failing as per https://ci.brave.com/job/pr-brave-browser-pr12711_ntp_si_imagecredit_cutoff_fixes_android_1.37.x-windows/1/testReport/(root)/RequestAdsEnabledApiTestEnabled/windows_x64___test_browser___RewardsEnablePopupAccepted/. However, this is a known intermittent failure as per brave/brave-browser#21809 and doesn't block uplift.

Linux failed due to the test-unit-chromium tests failing as per https://ci.brave.com/job/pr-brave-browser-pr12711_ntp_si_imagecredit_cutoff_fixes_android_1.37.x-linux/1/testReport. However, this is known and doesn't block uplift. DevOps fixing the above by restricting chromium tests to master as per https://github.com/brave/devops/pull/7195.

[kjozwiak]

Uplift into 1.37.x approved 👍 QA has verified the PR on Nightly as per #12711 (comment).