Make use of the jvm_opts from java_toolchain

-client is now the only default JVM options of JavaBuilder

--
MOS_MIGRATED_REVID=96762330
diff --git a/tools/jdk/BUILD b/tools/jdk/BUILD
index 8c1b257..de26dd9 100644
--- a/tools/jdk/BUILD
+++ b/tools/jdk/BUILD
@@ -73,6 +73,7 @@
 java_toolchain(
     name = "toolchain",
     encoding = "UTF-8",
+    jvm_opts = ["-client"],
     source_version = "7",
     target_version = "7",
 )