a11y: Ignore cursor area size when hovering panel

The users have the option to ignore curser movement up to a large
radius. However the panel's buttons are so close together that a large
ignore radius makes interacting with the panel difficult.

So only when hovering the panel, ignore the user's selected cursor area
and size and always trigger clicks using the default slop.

Also rename to `isPanelHovered()` to clarify what is hovered.

Bug: b/398257159
Test: AutoclickTypePanelTest
Flag: com.android.server.accessibility.enable_autoclick_indicator
Change-Id: If76197b8dec5076a5f34ea0fb60e75ba4857ec9b