OTA升级应用缓存不更新

 final File cacheBaseDir = Environment.getPackageCacheDirectory();
        if (!FileUtils.createDir(cacheBaseDir)) {
            return null;
        }

        // There are several items that need to be combined together to safely
        // identify cached items. In particular, changing the value of certain
        // feature flags should cause us to invalidate any caches.
        final String cacheName = FORCE_PACKAGE_PARSED_CACHE_ENABLED ? "debug"
                : SystemProperties.digestOf("ro.build.fingerprint");//文件夹的名称是通过这个生成的

        // Reconcile cache directories, keeping only what we'd actually use.
        for (File cacheDir : FileUtils.listFilesOrEmpty(cacheBaseDir)) {
            if (Objects.equals(cacheName, cacheDir.getName())) {//boyin 
            
                if(SystemProperties.get("persist.sys.ota_done","0").equals("1")){//添加标志位，需要对ota升级应用做修改，在升级成功后把这个标志位置为1
                    FileUtils.deleteContentsAndDir(cacheDir);
                    SystemProperties.set("persist.sys.ota_done","0");
                    Slog.d(TAG, "delete known cache ,升级成功:"   cacheDir.getName());
                }

                Slog.d(TAG, "Keeping known cache "   cacheDir.getName());
            } else {
                Slog.d(TAG, "Destroying unknown cache "   cacheDir.getName());
                FileUtils.deleteContentsAndDir(cacheDir);
            }
        }