RossWang

fix: extension does not initialize on startup

4

Persistent of background page is set to [false](https://github.com/AdguardTeam/AdguardBrowserExtension/blob/aaf9ff758ba7387ef41b9b7d8c703184b94d9b79/tools/bundle/firefox/manifest.firefox.ts#L45) in extension manifest on Firefox. Others should be fine with this modification. related #3176