Revert^2 "[SB][Notifs] status_bar_ron_chips flag -> status_bar_not..."

This reverts commit fd39d2a3.

Reason for revert: Metrics show the original CL was *not* cause for performance regression b/374191659
Bug: 374191659

Original CL description:
Removes "RON" from the flag name and instead makes the flag name more
generic.

Also updates all the "demo RON" code to be "demo notification" instead.

Bug: 364653005
Flag: com.android.systemui.status_bar_notification_chips
Test: all tests under statusbar package

Change-Id: I5b989106d2fcdaa522accf3d51459e8107766112