Autoclick: Fix position button panel test

This change resolves the test flake by waiting for the autoclick panel
to move as expected before attempting to click the position button
again.

Bug: 422376066
Test: atest AutoclickPanelTests
Flag: com.android.server.accessibility.enable_autoclick_indicator
Change-Id: I163008bc270b0d41b79920da5afe4f9078222ad3