Re-arranged some test cases

1. Removed meaningless test cases using the remote example jar as the tests will succeed even if there's any issue with downloading and mounting the remote example jar, as the example jar is available locally in the containers.
2. Added a new test case using the PageRank example with a remote data file and test secret mounted.

Author: liyinan926

integration-test/src/test/scala/org/apache/spark/deploy/k8s/integrationtest/KubernetesSuite.scala

@@ -40,9 +40,12 @@ private[spark] class KubernetesSuite extends FunSuite with BeforeAndAfterAll wit
   private var kubernetesTestComponents: KubernetesTestComponents = _
   private var sparkAppConf: SparkAppConf = _
 
-  private val driverImage = System.getProperty("spark.docker.test.driverImage", "spark-driver:latest")
-  private val executorImage = System.getProperty("spark.docker.test.executorImage", "spark-executor:latest")
-  private val initContainerImage = System.getProperty("spark.docker.test.initContainerImage", "spark-init:latest")
+  private val driverImage = System.getProperty("spark.docker.test.driverImage",
+    "spark-driver:latest")
+  private val executorImage = System.getProperty("spark.docker.test.executorImage",
+    "spark-executor:latest")
+  private val initContainerImage = System.getProperty("spark.docker.test.initContainerImage",
+    "spark-init:latest")
 
 
   override def beforeAll(): Unit = {
@@ -91,11 +94,6 @@ private[spark] class KubernetesSuite extends FunSuite with BeforeAndAfterAll wit
     runSparkPiAndVerifyCompletion(appArgs = Array("5"))
   }
 
-  test("Run SparkPi using the remote example jar.") {
-    sparkAppConf.set("spark.kubernetes.initContainer.image", initContainerImage)
-    runSparkPiAndVerifyCompletion(appResource = REMOTE_EXAMPLES_JAR_URI)
-  }
-
   test("Run SparkPi with custom driver pod name, labels, annotations, and environment variables.") {
     sparkAppConf
       .set("spark.kubernetes.driver.pod.name", "spark-integration-spark-pi")
@@ -140,17 +138,30 @@ private[spark] class KubernetesSuite extends FunSuite with BeforeAndAfterAll wit
       })
   }
 
-  test("Run SparkPi using the remote example jar with a test secret mounted into the driver and " +
-    "executor pods") {
+  test("Run PageRank using remote data file") {
     sparkAppConf
+      .set("spark.kubernetes.mountDependencies.filesDownloadDir",
+        CONTAINER_LOCAL_FILE_DOWNLOAD_PATH)
+      .set("spark.files", REMOTE_PAGE_RANK_DATA_FILE)
+      .set("spark.kubernetes.initContainer.image", initContainerImage)
+    runSparkPageRankAndVerifyCompletion(
+      appArgs = Array(CONTAINER_LOCAL_DOWNLOADED_PAGE_RANK_DATA_FILE))
+  }
+
+  test("Run PageRank using remote data file with test secret mounted into the driver and " +
+    "executors") {
+    sparkAppConf
+      .set("spark.kubernetes.mountDependencies.filesDownloadDir",
+        CONTAINER_LOCAL_FILE_DOWNLOAD_PATH)
+      .set("spark.files", REMOTE_PAGE_RANK_DATA_FILE)
       .set(s"spark.kubernetes.driver.secrets.$TEST_SECRET_NAME", TEST_SECRET_MOUNT_PATH)
       .set(s"spark.kubernetes.executor.secrets.$TEST_SECRET_NAME", TEST_SECRET_MOUNT_PATH)
-    sparkAppConf.set("spark.kubernetes.initContainer.image", initContainerImage)
+      .set("spark.kubernetes.initContainer.image", initContainerImage)
 
     createTestSecret()
 
-    runSparkPiAndVerifyCompletion(
-      appResource = REMOTE_EXAMPLES_JAR_URI,
+    runSparkPageRankAndVerifyCompletion(
+      appArgs = Array(CONTAINER_LOCAL_DOWNLOADED_PAGE_RANK_DATA_FILE),
       driverPodChecker = (driverPod: Pod) => {
         doBasicDriverPodCheck(driverPod)
         checkTestSecret(driverPod, withInitContainer = true)
@@ -161,14 +172,6 @@ private[spark] class KubernetesSuite extends FunSuite with BeforeAndAfterAll wit
       })
   }
 
-  test("Run PageRank using remote data file") {
-    sparkAppConf
-      .set("spark.kubernetes.mountDependencies.filesDownloadDir", CONTAINER_LOCAL_FILE_DOWNLOAD_PATH)
-      .set("spark.files", REMOTE_PAGE_RANK_DATA_FILE)
-      .set("spark.kubernetes.initContainer.image", initContainerImage)
-    runSparkPageRankAndVerifyCompletion(appArgs = Array(CONTAINER_LOCAL_DOWNLOADED_PAGE_RANK_DATA_FILE))
-  }
-
   private def runSparkPiAndVerifyCompletion(
       appResource: String = CONTAINER_LOCAL_SPARK_DISTRO_EXAMPLES_JAR,
       driverPodChecker: Pod => Unit = doBasicDriverPodCheck,
@@ -322,9 +325,6 @@ private[spark] object KubernetesSuite {
 
   val CONTAINER_LOCAL_FILE_DOWNLOAD_PATH = "/var/spark-data/spark-files"
 
-  val REMOTE_EXAMPLES_JAR_URI =
-    "https://storage.googleapis.com/spark-k8s-integration-tests/jars/spark-examples_2.11-2.3.0.jar"
-
   val REMOTE_PAGE_RANK_DATA_FILE =
     "https://storage.googleapis.com/spark-k8s-integration-tests/files/pagerank_data.txt"
   val CONTAINER_LOCAL_DOWNLOADED_PAGE_RANK_DATA_FILE =