[SPARKR][HOTFIX] Disable flaky SparkR package build test

See https://github.com/apache/spark/pull/9390#issuecomment-157160063 and https://gist.github.com/shivaram/3a2fecce60768a603dac for more information

Author: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

Closes #9744 from shivaram/sparkr-package-test-disable.

core/src/test/scala/org/apache/spark/deploy/SparkSubmitSuite.scala

@@ -369,7 +369,9 @@ class SparkSubmitSuite
     }
   }
 
-  test("correctly builds R packages included in a jar with --packages") {
+  // TODO(SPARK-9603): Building a package is flaky on Jenkins Maven builds.
+  // See https://gist.github.com/shivaram/3a2fecce60768a603dac for a error log
+  ignore("correctly builds R packages included in a jar with --packages") {
     assume(RUtils.isRInstalled, "R isn't installed on this machine.")
     val main = MavenCoordinate("my.great.lib", "mylib", "0.1")
     val sparkHome = sys.props.getOrElse("spark.test.home", fail("spark.test.home is not set!"))