This is a welcome development. ProtonMail has worked well for me. Now if I could only find a way to make a Pixel phone accept that email address instead of one of my several one-off fake name gmail addresses that I use for such things.
Don't integrate privacy-focused email service (hushmail/proton etc) into a non-private phone. Access it via the webmail interface.
I've been asked several times to decrypt my phone at international boarders. If you leave things to webmail, unlocking your phone doesn't give them access to your email account, or even tell them where it is. All the TSA/Cops get is my "[email protected]" address that I haven't checked since day one with the phone. My access to my real email is covered by a web browser that doesn't keep records.
If memory serves you can create a Google account with your existing email address. They won’t create a gmail account for you, but you can still use other Google services with it. I’m guessing it’s worth trying with your Android phone?