Move ENABLE_HIDE_GBOARD_HEADER_STATIC from feature flag to server side flag.

Bug: 266708932
Test: manual with adb command
Change-Id: Id064367ee970120cf0aa668b9c81613f7262bad8
diff --git a/src/com/android/launcher3/config/FeatureFlags.java b/src/com/android/launcher3/config/FeatureFlags.java
index c328554..c90c6bf 100644
--- a/src/com/android/launcher3/config/FeatureFlags.java
+++ b/src/com/android/launcher3/config/FeatureFlags.java
@@ -96,9 +96,6 @@
             "ENABLE_EXPANDING_PAUSE_WORK_BUTTON", false,
             "Expand and collapse pause work button while scrolling");
 
-    public static final BooleanFlag ENABLE_HIDE_HEADER_STATIC = new DeviceFlag(
-            "ENABLE_HIDE_HEADER_STATIC", false, "Hide keyboard suggestion strip");
-
     public static final BooleanFlag COLLECT_SEARCH_HISTORY = new DeviceFlag(
             "COLLECT_SEARCH_HISTORY", false, "Allow launcher to collect search history for log");