test(bigtable): disable testDeadlockPrevention to fix CI execution timeout (#13902)

Disable flaky test
(#13903). Bigtable
unit tests are run as part of the main units test suite. This is causing
some of our required checks to timeout after ~360 minutes. Disable flaky
tests to be re-enabled after they get resolved.

Author: lqiu96

java-bigtable/google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/data/v2/internal/util/ClientConfigurationManagerTest.java

@@ -63,6 +63,7 @@
 import java.util.concurrent.atomic.AtomicReference;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.ArgumentCaptor;
@@ -335,6 +336,7 @@ void testSysPropOverrideSessionLoadZero() throws Exception {
     assertThat(initialConfig).isEqualTo(service.config.get());
   }
 
+  @Disabled("https://github.com/googleapis/google-cloud-java/issues/13903")
   @Test
   void testDeadlockPrevention() throws Exception {
     // Initialize the manager and fetch the initial config to schedule polling.