test: temporarily disable flaky test (#2440)

Change-Id: I6d23530f0590faef67869da66da7fda0b0ffa73b

Author: igorbernstein2

google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/it/BuiltinMetricsIT.java

@@ -70,6 +70,7 @@
 import org.junit.After;
 import org.junit.Before;
 import org.junit.ClassRule;
+import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.Timeout;
@@ -78,6 +79,7 @@
 import org.threeten.bp.Duration;
 import org.threeten.bp.Instant;
 
+@Ignore("Temporarily disable flaky test")
 @RunWith(JUnit4.class)
 public class BuiltinMetricsIT {
   @ClassRule public static TestEnvRule testEnvRule = new TestEnvRule();