Check whether feature is enabled by compare with apex version

Replace the isFeatureEnabled function which is check with apex version.

Bug: 187946226
Test: Set device config flag and check the result
Change-Id: Iba44a01e2fdd0698dcb338ea4a8fe8147cbaa7dd
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index 413b0cb..2beeeb8 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -58,6 +58,8 @@
 
     private static final String[] EMPTY_STRING_ARRAY = new String[0];
 
+    private static final String TETHERING_MODULE_NAME = "com.android.tethering";
+
     // Default ranges used for the legacy DHCP server.
     // USB is  192.168.42.1 and 255.255.255.0
     // Wifi is 192.168.43.1 and 255.255.255.0
@@ -473,7 +475,8 @@
 
     @VisibleForTesting
     protected boolean isFeatureEnabled(Context ctx, String featureVersionFlag) {
-        return DeviceConfigUtils.isFeatureEnabled(ctx, NAMESPACE_CONNECTIVITY, featureVersionFlag);
+        return DeviceConfigUtils.isFeatureEnabled(ctx, NAMESPACE_CONNECTIVITY, featureVersionFlag,
+                TETHERING_MODULE_NAME, false /* defaultEnabled */);
     }
 
     private Resources getResources(Context ctx, int subId) {