Fix hub touch handling interfering with bouncer swipe on dream

The dream overlay intercepts touches globally to implement the bouncer
swipe up gesture. However, the hub's touch handling does not intercept
those touches, meaning they fall through to the shade window and are
also processed as a swipe for the shade. This caused occasional issues
where swiping up on the hub over the dream would briefly show the
bouncer then start showing the notification shade instead.

This fix makes the hub touches near the top and bottom when dreaming to
fix this specific issue, but does not implement a long-term solution
for gesture handling over the hub.

Bug: 327679394
Fixed: 327679394
Test: atest GlanceableHubContainerControllerTest
      see video in bug for demo
Flag: ACONFIG com.android.systemui.communal_hub TEAMFOOD
Change-Id: I7175f037744a6b62197bd1ff3868a081d8fc4c3a