ci: fix kokoro windows build scripts (GoogleContainerTools#3979)

* Java 8 issue: updated scripts to use the new environment's default JAVA_HOME and removes the previously set location.
* BuildFilesTest issue: switched test to unix-based newline instead of System.lineSeparator() in BuildFilesTest.
* UpdateCheckerTest issue: added extra lag time between operations in UpdateCheckerTest with before/after timestamp comparison.

jib-cli/src/test/java/com/google/cloud/tools/jib/cli/buildfile/BuildFilesTest.java

@@ -183,8 +183,7 @@ public void testToBuildFileSpec_templateMultiLineBehavior()
         Paths.get(Resources.getResource("buildfiles/projects/templating/multiLine.yaml").toURI());
 
     Mockito.when(buildCli.getTemplateParameters())
-        .thenReturn(
-            ImmutableMap.of("replace" + System.lineSeparator() + "this", "creationTime: 1234"));
+        .thenReturn(ImmutableMap.of("replace" + "\n" + "this", "creationTime: 1234"));
     JibContainerBuilder jibContainerBuilder =
         BuildFiles.toJibContainerBuilder(
             buildfile.getParent(), buildfile, buildCli, commonCliOptions, consoleLogger);

jib-plugins-common/src/test/java/com/google/cloud/tools/jib/plugins/common/UpdateCheckerTest.java

@@ -68,8 +68,9 @@ public void tearDown() throws IOException {
   }
 
   @Test
-  public void testPerformUpdateCheck_newVersionFound() throws IOException {
+  public void testPerformUpdateCheck_newVersionFound() throws IOException, InterruptedException {
     Instant before = Instant.now();
+    Thread.sleep(100);
     setupLastUpdateCheck();
     Optional<String> message =
         UpdateChecker.performUpdateCheck(
@@ -99,8 +100,9 @@ public void testPerformUpdateCheck_newJsonField()
   }
 
   @Test
-  public void testPerformUpdateCheck_onLatest() throws IOException {
+  public void testPerformUpdateCheck_onLatest() throws IOException, InterruptedException {
     Instant before = Instant.now();
+    Thread.sleep(100);
     setupLastUpdateCheck();
     Optional<String> message =
         UpdateChecker.performUpdateCheck(
@@ -115,8 +117,9 @@ public void testPerformUpdateCheck_onLatest() throws IOException {
   }
 
   @Test
-  public void testPerformUpdateCheck_noLastUpdateCheck() throws IOException {
+  public void testPerformUpdateCheck_noLastUpdateCheck() throws IOException, InterruptedException {
     Instant before = Instant.now();
+    Thread.sleep(100);
     Optional<String> message =
         UpdateChecker.performUpdateCheck(
             configDir, "1.0.2", testWebServer.getEndpoint(), "tool-name", ignored -> {});
@@ -129,9 +132,11 @@ public void testPerformUpdateCheck_noLastUpdateCheck() throws IOException {
   }
 
   @Test
-  public void testPerformUpdateCheck_emptyLastUpdateCheck() throws IOException {
+  public void testPerformUpdateCheck_emptyLastUpdateCheck()
+      throws IOException, InterruptedException {
     Files.createFile(configDir.resolve("lastUpdateCheck"));
     Instant before = Instant.now();
+    Thread.sleep(100);
     Optional<String> message =
         UpdateChecker.performUpdateCheck(
             configDir, "1.0.2", testWebServer.getEndpoint(), "tool-name", ignored -> {});
@@ -164,8 +169,9 @@ public void testPerformUpdateCheck_lastUpdateCheckTooSoon() throws IOException {
   }
 
   @Test
-  public void testPerformUpdateCheck_badLastUpdateTime() throws IOException {
+  public void testPerformUpdateCheck_badLastUpdateTime() throws IOException, InterruptedException {
     Instant before = Instant.now();
+    Thread.sleep(100);
     Files.write(
         configDir.resolve("lastUpdateCheck"), "bad timestamp".getBytes(StandardCharsets.UTF_8));
     Optional<String> message =

kokoro/continuous.bat

@@ -1,8 +1,7 @@
 @echo on
 
 REM Java 9 does not work with Mockito mockmaker.
-set JAVA_HOME=c:\program files\java\jdk1.8.0_152
-set PATH=%JAVA_HOME%\bin;%PATH%
+echo %JAVA_HOME%
 
 cd github/jib
 

kokoro/presubmit.bat

@@ -1,8 +1,7 @@
 @echo on
 
 REM Java 9 does not work with Mockito mockmaker.
-set JAVA_HOME=c:\program files\java\jdk1.8.0_152
-set PATH=%JAVA_HOME%\bin;%PATH%
+echo %JAVA_HOME%
 
 cd github/jib