Bigtable: clean up client side metrics flag

Author: mutianf

sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigtable/BigtableServiceFactory.java

@@ -51,9 +51,6 @@ class BigtableServiceFactory implements Serializable {
   private static final ConcurrentHashMap<UUID, AtomicInteger> refCounts = new ConcurrentHashMap<>();
   private static final Object lock = new Object();
 
-  private static final String BIGTABLE_ENABLE_CLIENT_SIDE_METRICS =
-      "bigtable_enable_client_side_metrics";
-
   private static final String BIGTABLE_ENABLE_SKIP_LARGE_ROWS = "bigtable_enable_skip_large_rows";
 
   @AutoValue
@@ -130,11 +127,6 @@ BigtableServiceEntry getServiceForReading(
           BigtableConfigTranslator.translateReadToVeneerSettings(
               config, opts, optsFromBigtableOptions, pipelineOptions);
 
-      if (ExperimentalOptions.hasExperiment(pipelineOptions, BIGTABLE_ENABLE_CLIENT_SIDE_METRICS)) {
-        LOG.info("Enabling client side metrics");
-        BigtableDataSettings.enableBuiltinMetrics();
-      }
-
       boolean skipLargeRows =
           ExperimentalOptions.hasExperiment(pipelineOptions, BIGTABLE_ENABLE_SKIP_LARGE_ROWS);
 
@@ -181,11 +173,6 @@ BigtableServiceEntry getServiceForWriting(
           BigtableConfigTranslator.translateWriteToVeneerSettings(
               config, opts, optsFromBigtableOptions, pipelineOptions);
 
-      if (ExperimentalOptions.hasExperiment(pipelineOptions, BIGTABLE_ENABLE_CLIENT_SIDE_METRICS)) {
-        LOG.info("Enabling client side metrics");
-        BigtableDataSettings.enableBuiltinMetrics();
-      }
-
       BigtableService service = new BigtableServiceImpl(settings);
       entry = BigtableServiceEntry.create(configId, service);
       entries.put(configId.id(), entry);