Handle JAVA_HOME with spaces

--
MOS_MIGRATED_REVID=113356411
diff --git a/scripts/bootstrap/compile.sh b/scripts/bootstrap/compile.sh
index 461c207..ee2481a 100755
--- a/scripts/bootstrap/compile.sh
+++ b/scripts/bootstrap/compile.sh
@@ -214,7 +214,7 @@
 
 # bazel build using bootstrap version
 function bootstrap_build() {
-  $JAVA_HOME/bin/java \
+  "${JAVA_HOME}/bin/java" \
       -client -Xms256m -XX:NewRatio=4 -XX:+HeapDumpOnOutOfMemoryError -Xverify:none -Dfile.encoding=ISO-8859-1 \
       -XX:HeapDumpPath=${OUTPUT_DIR} \
       -Djava.util.logging.config.file=${OUTPUT_DIR}/javalog.properties \