End live tile when invoking Circle to Search over Overview.

This fixes many animation/state issues related to switching tasks
from the live tile to AGA.

Demo before: https://drive.google.com/file/d/1aBsn_-4tRHRsfGSqsx44_1B7dgdPOq_v/view?usp=drive_link&resourcekey=0-EHyEiKRVEC2ooUo-0rcjHg
Demo after: https://drive.google.com/file/d/1Sf5cUh8hC-slUZc_efOChzxxw710pG65/view?usp=drive_link&resourcekey=0-Wr33tL3ytedMibcVNd6auw

Bug: 372592549
Bug: 297831970
Test: Manual, updated ContextualSearchInvokerTest.
Flag: EXEMPT bugfix
Change-Id: I538cb1de61e48de4cf7c6fca8710a655933d07a3