Fix Java types.hal generation filtering

Bug: 31470959
Change-Id: I9312ad5a73289d829548a93491a8353abf9a451a
diff --git a/AST.h b/AST.h
index 1360e7e..59fb62c 100644
--- a/AST.h
+++ b/AST.h
@@ -74,10 +74,12 @@
     status_t generateCppImpl(const std::string &outputPath) const;
 
     status_t generateJava(
-            const std::string &outputPath, const char *limitToType) const;
+            const std::string &outputPath,
+            const std::string &limitToType) const;
 
     status_t generateJavaTypes(
-            const std::string &outputPath, const char *limitToType) const;
+            const std::string &outputPath,
+            const std::string &limitToType) const;
 
     void getImportedPackages(std::set<FQName> *importSet) const;