Fix isSystemUi to avoid System services

We previously switched to checking just status bar permission to
determine whether a service was system UI, but system services also pass
the status bar permissions check, so we still need to retain the
!isCallerSystemOrPhone check.

Bug: 299448097
Test: Flash+build manual test
Flag: ACONFIG android.app.lifetime_extension_refactor STAGING
Change-Id: I8a4304781f4e1bc4f52c9d7b14381d78a8ad5f1d
diff --git a/services/core/java/com/android/server/notification/NotificationManagerService.java b/services/core/java/com/android/server/notification/NotificationManagerService.java
index ba5882c..7042bdd 100755
--- a/services/core/java/com/android/server/notification/NotificationManagerService.java
+++ b/services/core/java/com/android/server/notification/NotificationManagerService.java
@@ -12050,10 +12050,17 @@
         @Override
         public void onServiceAdded(ManagedServiceInfo info) {
             if (lifetimeExtensionRefactor()) {
-                // We explicitly check the status bar permission for the uid in the info object.
-                // We can't use the calling uid here because it's probably always system server.
-                // Note that this will also be true for the shell.
-                info.isSystemUi = getContext().checkPermission(
+                // Generally, only System or System UI should have the permissions to call
+                // registerSystemService.
+                // isCallerSystemOrPhone tells us whether the caller is System. We negate this,
+                // to eliminate cases where the service was added by the system. This leaves
+                // services registered by system server.
+                // To identify system UI, we explicitly check the status bar permission for the
+                // uid in the info object.
+                // We can't use the calling uid here because it belongs to system server.
+                // Note that this will also return true for the shell, but we deem this
+                // acceptable, for the purposes of testing.
+                info.isSystemUi = !isCallerSystemOrPhone() && getContext().checkPermission(
                         android.Manifest.permission.STATUS_BAR_SERVICE, -1, info.uid)
                         == PERMISSION_GRANTED;
             }