Make flags UI available on release build of launcher

The UI will only be shown on eng/userdebug platform builds.

Bug: 117223984
Change-Id: I27843f2d856a4a19f3fe53c4d306606eaa5714a2
diff --git a/src/com/android/launcher3/MainProcessInitializer.java b/src/com/android/launcher3/MainProcessInitializer.java
index 0028f97..a18dfde 100644
--- a/src/com/android/launcher3/MainProcessInitializer.java
+++ b/src/com/android/launcher3/MainProcessInitializer.java
@@ -18,6 +18,7 @@
 
 import android.content.Context;
 
+import com.android.launcher3.config.FeatureFlags;
 import com.android.launcher3.graphics.IconShapeOverride;
 import com.android.launcher3.logging.FileLog;
 import com.android.launcher3.util.ResourceBasedOverride;
@@ -35,6 +36,7 @@
 
     protected void init(Context context) {
         FileLog.setDir(context.getApplicationContext().getFilesDir());
+        FeatureFlags.initialize(context);
         IconShapeOverride.apply(context);
         SessionCommitReceiver.applyDefaultUserPrefs(context);
     }