[Wi-Fi] Release the camera before opening

As per the Google's design mentioned at
https://developer.android.com/training/camera/cameradirect.html


Calling Camera.open() throws an exception
if the camera is already in use by another application,
so we wrap it in a try block one must release the camera before opening

Bug: 141662635
Test: Manual occurs once while testing 10 times
1.Open wifi settings,tap QR code icon
2.Make a incoming VoLTE call,tap incoming VoLTE call dialog
3.Check device
Signed-off-by: JeiFeng Lee <linger.lee@mediatek.com>

Change-Id: Ief62600af8b745cb4eae2e5ae277a2cebdda68eb