I have Google Maps in my Android App. I added it by selecting new Google Maps Activity & pasting the key in Android Studio. It worked fine in my Android phone (Lenovo K5
I had similar problem and spent a lot of time before solving it. Usually all was OK on real device, but failed to show Google Map on some of my emulator variants. Obviously, the program code was OK, so the question was why?
What I observe so far:
If hardware acceleration is disabled - all is back working.
If use pure android image, cpu-arm (not accelerated x86, it was slower), but also works.
If you are under x86_64 OS - macOS 10.13.2 in my case, USE x86_64 version of emulator image, instead of universal x86!!! That was my mayor mistake to do not get it works! Replacing my emulator's image with x86_64 variants, solve all of them!