Yes, if someone hack your google account, they will be able to get the master password to get into your password manager vault. If you had one done that, they would need to hack your password manager password before they can get into your vault. You should definitely turn off password saving on the browser and let the password manager handle the password.
I turn those features off, especially the in-browser password remember systems. For one thing, if you have BW, why do you need the secondary password system. Is there a security hazard? Probably not, but it can’t possibly be more secure to have a password saved in two places. Twice the potential for being hacked.
On a side note, I didn’t even know Google had this feature. Must be new.
You should not store your master password in Google.
Also, disable google autofill and save all passwords in Bitwarden. To disable the google autofill on android, visit General FAQs | Bitwarden Help & Support
Google Chrome has been “helpfully” storing passwords for years, if not decades. Once the passwords are extracted from it people should turn off this “helpful” feature and exterminate the passwords already stored in it.
While people are at it I would suggest they look at what information Google is “helpfully” storing (unencrypted) on Google computers.
Now Google is not all bad. I do have their free drive which I keep some things on. They are welcome to try and breach the encryption on my files, I am not foolish enough to store unencrypted stuff on their computers for them to spy on.