Fix: The custom tabs pixel validation

[0nko]

Task/Issue URL: https://app.asana.com/1/137249556945/project/1207418217763355/task/1212406760963050?focus=true

Description

This PR fixes the custom tabs pixel validation JSON, because it failed the live validation.

Steps to test this PR

QA-optional

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Note

Replace first_daily_count with daily_count_short in m_custom_tabs_address_bar_clicked pixel suffixes (PixelDefinitions/pixels/custom_tabs.json5).

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