autoclick: Fix autoclick scroll panel exit button not reverting to left-click

Problem: Manual click on scroll panel's "Close" button doesn't revert to
left-click when setting is enabled, while hover wait autoclick on exit
button does.

Cause: Manual close only calls hide(), not exitScrollMode() which
contains the revert logic.

Fix: Route both exit paths through exitScrollMode() in controller

Video: http://shortn/_vlg8H26GTB

Bug: b/421211294
Test: atest
Flag: com.android.server.accessibility.enable_autoclick_indicator
Change-Id: I4f24a200da0e7b97ba552750ad10ef002030486d