test(bigtable): use single instance for MV tests

Author: ron-gal

google-cloud-bigtable/src/test/java/com/google/cloud/bigtable/admin/v2/it/BigtableMaterializedViewIT.java

@@ -56,44 +56,23 @@ public class BigtableMaterializedViewIT {
   private static final int[] BACKOFF_DURATION = {2, 4, 8, 16, 32, 64, 128, 256, 512, 1024};
 
   private static BigtableInstanceAdminClient client;
-  private static BigtableTableAdminClient tableAdminClient;
   private static Table testTable;
-  private static String instanceId = "";
+  private String instanceId = testEnvRule.env().getInstanceId();
 
   // TODO: Update this test once emulator supports InstanceAdmin operation
   // https://github.com/googleapis/google-cloud-go/issues/1069
   @BeforeClass
-  public static void validatePlatform() throws IOException {
+  public static void validatePlatform() {
     assume()
         .withMessage("BigtableInstanceAdminClient doesn't support on Emulator")
         .that(testEnvRule.env())
         .isNotInstanceOf(EmulatorEnv.class);
-
-    createInstance();
-  }
-
-  public static void createInstance() throws IOException {
-    client = testEnvRule.env().getInstanceAdminClient();
-
-    Instance instance =
-        client.createInstance(
-            CreateInstanceRequest.of(new PrefixGenerator().newPrefix())
-                .addCluster("my-cluster", "us-east1-c", 3, StorageType.SSD));
-    instanceId = instance.getId();
-    tableAdminClient =
-        BigtableTableAdminClient.create(testEnvRule.env().getProjectId(), instanceId);
-  }
-
-  @AfterClass
-  public static void deleteInstance() {
-    if (!instanceId.isEmpty()) {
-      client.deleteInstance(instanceId);
-    }
   }
 
   @Before
   public void setUp() throws InterruptedException {
-    testTable = createTestTable(tableAdminClient);
+    client = testEnvRule.env().getInstanceAdminClient();
+    testTable = createTestTable(testEnvRule.env().getTableAdminClient());
   }
 
   @Test