You can check FiLMic Pro for the video. It’s not free whoever they have a free app that will tell you which features of FiLMic Pro the phone supports.
I’m haven’t been in the Android world for a while now. I know FiLMic Pro allows me to change cameras on my phone.
Also, regarding photos, I would suggest you check out some of the available 3rd party camera apps that are available. I know some allow you to switch cameras and also will make photos in raw. I don’t have any suggestions on which ones. I simply don’t remember much about the Android camera apps.
I still have a Mate 9 but have not used it in a long time. Maybe I’ll knock the dust off of it, fire it up and see if I can remember anything.
BTW, FiLMic Pro is one of the best, if not the best, video apps around. You have full manual control, resolution, frame rate, bit rate, aspect ratio (even 2.39 which is true cinematic ratio and coupled with 24 FPS produces some great cin video) and it even allows you to film in flat gamma and log gamma if you want. That’s so great for color grading in post processing adjusting yourself or using LUTs. Again this all depends on which feature the phone has.