We are replacing firebase kits with HMS kits for HMS based mobiles (noGMS) for our app.
However, we still would like to stick and use Firebase/Google Analytics for analyzing user behaviors and logging specific events from huawei mobiles?
How it could be achieved? is there any workaround to do that?
Yes its possible to forward analytics data straight to Firebase using Huawei Analytics and DTM Kits. Not only that you can also forward analytics data to third party tool as well. As shown in this table: 
For more details please visit this link
You can refer to the official https://firebase.google.com/docs/android/android-play-services. According to that page:
The Firebase SDK for Google Analytics can send events on any device, but some automatic insights such as demographics are only available on devices with Google Play services.
Base on your needs, you can decide if you want to keep using GA with limited functionalities, or to forward analytics data from Huawei Analytics -> Firebase/Google Analytics as sAm suggested
