High Level Android Developer - Help needed

[Heinfreis]

Hi All

a bit of history as to why I'm posting this here. (apologize) We are currently a Hardware manufacturing company. We developed a 5" industrial handheld device based on the Android 7 platforms since then the 3rd party supplier isn't willing to help (even if we offer to pay) to develop a new updated version of the OS e.g. 8 or 9. We have been given a massive amount of source code from the supplier who told us it is your responsibility now. The problem is we only have software developers and not system builders in our software dept and even the software guys are sometimes challenged.
We have updated the flash/LED light (hardware) by developing a serial device that now uses a set of commands to control how the lights work via a Serial USB terminal. The lights work well but we are experiencing terrible quality issues. The hardware is still sending the trigger (flash) when using the built-in camera app but the camera doesn't have time to focus or set exposure especially when we take photos in low light conditions. If we use the application we developed using a similar "cameraview", we have some success with this. When we turn on the lights and then take a photo it turns out great, but it seems one of our clients is not very happy with this approach and we will have to come up with a more reliable way to sync the light system and camera flash trigger. What we need is for the system to activate the lights(flash) wait for the camera to focus set exposure etc. and then trigger the picture, does anyone knows how or what we would need to look at to achieve this and could this be possible with this Cameraview using Camera 2?