The standard and most consistent way to do so is to click the Edit button in the upper-right corner (looks like a little ...
The Google Phone app is getting a lot more like the iPhone's. First, there was the new, iPhone-inspired horizontal swipe-to-answer gesture, but less controversially, there's also now full-screen ...
To use Google Phone Calling Card for an iPhone-like calling screen, update the Google Phone app to v188 or later, then go to Settings > Calling Card, pick a contact, and customize with full-screen ...