[ads] Browser should resign active when closing the last tab

[tmancey]

Description

Browser should resign active when closing the last tab

Steps to reproduce

1. Join Brave Rewards
2. Close all tabs

Actual result

Browser did resign active does not appear in the logs

Expected result

Browser did resign active should appear in the logs

Reproduces how often

Easily reproduced

Desktop Brave version (brave://version info)

1.68.x

Android device

• Brand/model: N/A
• Android version: N/A

Channel information

• release (stable)
• beta
• nightly

Reproducibility

• with Brave Shields disabled
• with Brave Rewards disabled
• in the latest version of Chrome

Miscellaneous information

No response