Add flag for making ModifierShortcutManager multiuser aware.

Bug: 351963350
Flag: com.android.server.flags.modifier_shortcut_manager_multiuser
Test: NA
Change-Id: I3bae98bc97c00afcc830e98fdd6bc0eca959fb5f
diff --git a/services/core/java/com/android/server/flags/services.aconfig b/services/core/java/com/android/server/flags/services.aconfig
index d387828..c361aee 100644
--- a/services/core/java/com/android/server/flags/services.aconfig
+++ b/services/core/java/com/android/server/flags/services.aconfig
@@ -35,3 +35,13 @@
     description: "Enable BackgroundInstallControl based on system feature to prevent it from starting on form factors."
     bug: "340928990"
 }
+
+flag {
+    namespace: "input"
+    name: "modifier_shortcut_manager_multiuser"
+    description: "Update Modifier Shortcut Manager to work correctly with multiple users, including HSUM"
+    bug: "351963350"
+    metadata {
+        purpose: PURPOSE_BUGFIX
+    }
+}