Don't run ijar test with JDK7

Those tests requires JDK8 features, just ignore them.

--
MOS_MIGRATED_REVID=135264862
diff --git a/third_party/ijar/test/BUILD b/third_party/ijar/test/BUILD
index b05f9ce..2687888 100644
--- a/third_party/ijar/test/BUILD
+++ b/third_party/ijar/test/BUILD
@@ -45,7 +45,10 @@
         "//tools/jdk:langtools",
     ],
     shard_count = 5,
-    tags = ["zip"],
+    tags = [
+        "jdk8",
+        "zip",
+    ],
 )
 
 sh_test(