Add feature flag to control whether to inject fallback app results when AiAi fails to return app corpus results.

Bug: 255355348
Test: manual
Change-Id: Ic314f2f7fb1939f470b687d1f869753489ae8da6
diff --git a/src/com/android/launcher3/config/FeatureFlags.java b/src/com/android/launcher3/config/FeatureFlags.java
index 9607da8..cdf7536 100644
--- a/src/com/android/launcher3/config/FeatureFlags.java
+++ b/src/com/android/launcher3/config/FeatureFlags.java
@@ -128,6 +128,10 @@
             "FOLDER_NAME_MAJORITY_RANKING", true,
             "Suggests folder names based on majority based ranking.");
 
+    public static final BooleanFlag INJECT_FALLBACK_APP_CORPUS_RESULTS = new DeviceFlag(
+            "INJECT_FALLBACK_APP_CORPUS_RESULTS", false, "Inject "
+            + "fallback app corpus result when AiAi fails to return it.");
+
     public static final BooleanFlag ASSISTANT_GIVES_LAUNCHER_FOCUS = getDebugFlag(
             "ASSISTANT_GIVES_LAUNCHER_FOCUS", false,
             "Allow Launcher to handle nav bar gestures while Assistant is running over it");