fix tests - dont try to fetch credentials when the client doesnt need them part 2

Change-Id: I7b446d2f0e5951a160659dd628c9ef00f47af04c

Author: igorbernstein2

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/internal/api/Client.java

@@ -94,12 +94,11 @@ public static Client create(ClientSettings settings) throws IOException {
     // TODO: compat layer: get this from settings
     String universeDomain = "googleapis.com";
 
-    GoogleCredentials credentials = GoogleCredentials.getApplicationDefault();
-
     Metrics metrics;
     if (settings.getChannelProvider() instanceof ChannelProviders.EmulatorChannelProvider) {
       metrics = new NoopMetrics();
     } else {
+      GoogleCredentials credentials = GoogleCredentials.getApplicationDefault();
       MetricRegistry registry = new MetricRegistry();
       OpenTelemetrySdk otel =
           MetricsImpl.createBuiltinOtel(