Remove unnecessary InternalSharedXdsClientPoolProvider.getOrCreate() overload

Author: AshZhang

xds/src/main/java/io/grpc/xds/InternalSharedXdsClientPoolProvider.java

@@ -46,11 +46,6 @@ public static ObjectPool<XdsClient> getOrCreate(String target, MetricRecorder me
     return getOrCreate(target, metricRecorder, null);
   }
 
-  public static ObjectPool<XdsClient> getOrCreate(
-      String target, CallCredentials transportCallCredentials) throws XdsInitializationException {
-    return getOrCreate(target, new MetricRecorder() {}, transportCallCredentials);
-  }
-
   public static ObjectPool<XdsClient> getOrCreate(
       String target, MetricRecorder metricRecorder, CallCredentials transportCallCredentials)
       throws XdsInitializationException {