[SB][Notifs] Add PromotedNotificationsProvider to auto-promote notifs.

PromotedNotificationsProvider is an interface with a single method,
`shouldPromote(entry: NotificationEntry): Boolean` that lets us
tell which notifications should be promoted. In AOSP, it just promotes
notifications with the FLAG_PROMOTED_ONGOING flag set.

Bug: 364653005
Flag: android.app.ui_rich_ongoing
Test: atest ActiveNotificationsInteractorTest
PromotedNotificationsProviderTest

Change-Id: I1913b65c79eb5a668a2f34e4ed2706595aed97f1
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index b0bd5b7..3d65522 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -468,6 +468,15 @@
 }
 
 flag {
+    name: "status_bar_notification_chips_test"
+    namespace: "systemui"
+    description: "Flag to enable certain features that let us test the status bar notification "
+        "chips with teamfooders. This flag should *never* be released to trunkfood or nextfood."
+    bug: "361346412"
+}
+
+
+flag {
     name: "compose_bouncer"
     namespace: "systemui"
     description: "Use the new compose bouncer in SystemUI"