Add Launcher aconfig.

Use `enable_expanding_pause_work_button` as an example.

See go/trunk-stable-launcher for implementation details

Bug: 294913042

Test: adb shell device_config put launcher com.google.android.platform.launcher.aconfig.flags.enable_expanding_pause_work_button true

Flag: enable_expanding_pause_work_button
Change-Id: I732722c8b219c023adf5bf31f132ce9da72fc4d5
diff --git a/src/com/android/launcher3/config/FeatureFlags.java b/src/com/android/launcher3/config/FeatureFlags.java
index 38aa387..2df20df 100644
--- a/src/com/android/launcher3/config/FeatureFlags.java
+++ b/src/com/android/launcher3/config/FeatureFlags.java
@@ -230,6 +230,7 @@
     public static final BooleanFlag ENABLE_HIDE_HEADER = getReleaseFlag(270390930,
             "ENABLE_HIDE_HEADER", ENABLED, "Hide header on keyboard before typing in all apps");
 
+    // Aconfig migration complete for ENABLE_EXPANDING_PAUSE_WORK_BUTTON.
     public static final BooleanFlag ENABLE_EXPANDING_PAUSE_WORK_BUTTON = getDebugFlag(270390779,
             "ENABLE_EXPANDING_PAUSE_WORK_BUTTON", DISABLED,
             "Expand and collapse pause work button while scrolling");