Disable camera button when camera is not detected

[zytegalaxy]

This is a UX improvement issue.

Issue: Currently in the data entry journey if the camera is not detected the user can still choose camera as an option to proceed to scan a QR code where the camera viewfinder is supposed to be shown but nothing happens (since camera is not present) after pressing the scan button.

Solution: We should change this such that the camera input option is disabled by graying out the camera icon/button and showing the following icon on it. We should use green background color for both camera and web UI options if available.