fix(spanner): Add logs

Author: sakthivelmanii

google-cloud-spanner/src/test/java/com/google/cloud/spanner/RetryOnInvalidatedSessionTest.java

@@ -60,7 +60,11 @@
 import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.TestRule;
+import org.junit.rules.TestWatcher;
+import org.junit.runner.Description;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
 import org.junit.runners.Parameterized.Parameter;
@@ -75,6 +79,22 @@ public Long apply(StructReader input) {
     }
   }
 
+  @Rule
+  public TestRule watcher =
+      new TestWatcher() {
+        protected void starting(Description description) {
+          System.out.println("Starting test: " + description.getMethodName());
+        }
+
+        protected void succeeded(Description description) {
+          System.out.println("Succeeded test: " + description.getMethodName());
+        }
+
+        protected void failed(Throwable e, Description description) {
+          System.out.println("Failed test: " + description.getMethodName());
+        }
+      };
+
   private static final ToLongTransformer TO_LONG = new ToLongTransformer();
 
   @Parameter(0)