is it right approach to create hybrid app using ionic with android studio web view…
It’s not really where our focus is.
http://ionicframework.com/docs/guide/preface.html
We’re focusing on using cordova/phonegap. I’ve done some really basic research into using android’s webview ([read this][1]) and it seems like it’s cordova without the plugins. That is, manually setting up hybrid-apps. Again, this is from my quick reading, so apologies if I’m missing some things 
Our api is tightly integrated with cordova’s functionality (cross-platform, native-functions through javascript, device-ready) so to sever that tie is going to create some issues. If you’ve manage to set things up successfully, than congrats ! But cordova is really the way to go.
I hope this clears some things up.
[1]: https://developer.chrome.com/multidevice/webview/gettingstarted