If someone will get access to my Coinomi wallet on Android 10 they can get access to my private keys?
Possible, but as for the technology used in coinomi wallet, hackers won't mind getting your private keys, they just need your recovery seed in able them to access your funds, which can be access on your coinomi account. Only possible if you didn't set a security to coinomi app.
In case of phone lost, import your recovery seed to a new installed coinomi app and transfer your funds to a new wallet asap to avoid future problems.