Modify string equal statement

Change the string equal statement to "".equals().

Test: m -j && m update-api
Change-Id: I6c7c4f61bdbfbf820b774f6e272f955106c57c54
diff --git a/src/com/android/xsdc/cpp/CppCodeGenerator.java b/src/com/android/xsdc/cpp/CppCodeGenerator.java
index 2615e84..f7ef86b 100644
--- a/src/com/android/xsdc/cpp/CppCodeGenerator.java
+++ b/src/com/android/xsdc/cpp/CppCodeGenerator.java
@@ -170,7 +170,7 @@
 
         for (XsdEnumeration tag : enums) {
             String value = tag.getValue();
-            if (value == "") {
+            if ("".equals(value)) {
                 value = "EMPTY";
             }
             headerFile.printf("%s,\n", Utils.toEnumName(value));
diff --git a/src/com/android/xsdc/java/JavaCodeGenerator.java b/src/com/android/xsdc/java/JavaCodeGenerator.java
index 943b64c..88a1141 100644
--- a/src/com/android/xsdc/java/JavaCodeGenerator.java
+++ b/src/com/android/xsdc/java/JavaCodeGenerator.java
@@ -128,7 +128,7 @@
                 out.printf("@java.lang.Deprecated\n");
             }
             String value = tag.getValue();
-            if (value == "") {
+            if ("".equals(value)) {
                 value = "EMPTY";
             }
             out.printf("\n%s(\"%s\"),", Utils.toEnumName(value), tag.getValue());