[dexopt] Fix: Convert with optional json array

Author: REAndroid

src/main/java/com/reandroid/dex/dexopt/ProfileMetadata.java

@@ -77,7 +77,7 @@ public JSONObject toJson() {
     @Override
     public void fromJson(JSONObject json) {
         name().set(json.getString("name"));
-        classList().fromJson(json.getJSONArray("classes"));
+        classList().fromJson(json.optJSONArray("classes"));
         setInitialized(true);
     }