How can i switch between camera when camera is previewing to the user?

[zdivyesh]

Please follow the following instructions before filing a bug:

1. Github issues under this project are only for sample-related issues. If you have modified the sample code in any way, then this is probably not the appropriate place to report a bug.
2. If you are trying to report a bug related to the CameraX library then you can do so at the Android Issue Tracker: https://issuetracker.google.com/components/618491.
3. Include the specific sample where you found the issue, in addition to device model and specific Android build number -- which can be found under Settings > About phone.
4. Include error logs from logcat, if there are any.
5. If you can, also attach a bug report-- but please keep in mind that personal information can sometimes be found in those, so double check before attaching.