Check java version in scripts running performance benchmarks.

Scripts throw exception if java version is not 1.8.*-internal

Bug:
Change-Id: I3c8487594ba15ef6b42433ba9bec2d22d5fa4a45
diff --git a/tools/run_on_app.py b/tools/run_on_app.py
index a207ed8..1dabbd3 100755
--- a/tools/run_on_app.py
+++ b/tools/run_on_app.py
@@ -100,6 +100,7 @@
     return os.path.abspath(f.name)
 
 def main(argv):
+  utils.check_java_version()
   app_provided_pg_conf = False;
   (options, args) = ParseOptions(argv)
   outdir = options.out