Moving the JAVA_BINARY variable to be initialized properly

Change-Id: Ief026fd72113b5db0d00d1c1db7b4c7100baa613
Test: ./cts-tradefed
Bug: 186811076
diff --git a/tools/cts-tradefed/etc/cts-tradefed b/tools/cts-tradefed/etc/cts-tradefed
index 117f4cd..b9d5547 100755
--- a/tools/cts-tradefed/etc/cts-tradefed
+++ b/tools/cts-tradefed/etc/cts-tradefed
@@ -55,12 +55,6 @@
   RDBG_FLAG=-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=${TF_DEBUG_PORT}
 fi
 
-JAVA_BINARY=${CTS_ROOT}/android-cts/jdk/bin/java
-
-if [ ! -f "${JAVA_BINARY}" ]; then
-    JAVA_BINARY=java
-fi
-
 # get OS
 HOST=`uname`
 if [ "$HOST" == "Linux" ]; then
@@ -92,6 +86,14 @@
     CTS_ROOT="$(dirname $(realpath $0))/../.."
 fi;
 
+if [ -z ${JAVA_BINARY} ]; then
+    JAVA_BINARY=${CTS_ROOT}/android-cts/jdk/bin/java
+fi;
+
+if [ ! -f "${JAVA_BINARY}" ]; then
+    JAVA_BINARY=java
+fi
+
 JAR_DIR=${CTS_ROOT}/android-cts/tools
 
 for JAR in ${JAR_DIR}/*.jar; do