docs: clarify delayed-contact coverage in the allowance toggle journey #1766

The description of journeys/allowances/allowances-turned-off.xml promises an Android delayed-contact-loading off/on check, but its seven actions perform only the ordinary toggle flow. A reviewer following the file cannot exercise that extra boundary.

Reported on #1686 at b6751e22956653c4f2a80112143880b47298e30d; still present at 43e0f3fe04705d397a81f493cf8e57239a0be73e. Original review thread.

Acceptance:

• Move the delayed-contact variant into an explicit manual-test note, or add executable actions with a supported way to hold and release contact loading. The standard runner currently has no such capability.
• Preserve the seven ordinary off/on actions and their Active-row assertion. Keep the shared journey name and prose aligned with iOS; document any intentional platform difference in the cross-platform table.
• Distinguish the ordinary journey from the held-boundary case in QA evidence. Do not label the latter passed because the seven existing actions or component tests pass.

This tracks a nonblocking LOW documentation finding under the repository's Review Findings policy. It does not reopen the repaired allowance activation code or resolve the separate terminal complete-WALLET backup finding.