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

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.
1. 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.
1. 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.
1. Include error logs from logcat, if there are any.
1. If you can, also attach a [bug report](https://developer.android.com/studio/debug/bug-report)-- but please keep in mind that personal information can sometimes be found in those, so double check before attaching.

L’issue non specifica alcun sample, file, test, dispositivo, build Android, log degli errori o passaggio per la riproduzione. Per prima cosa identifica il sample interessato e raccogli i dettagli richiesti sul dispositivo e su logcat; dal report attuale non è possibile stabilire né l’ambito dell’implementazione né i criteri di completamento.

Scritto dal modello di indicizzazione a partire dal testo della issue.