Performance and resource recommendations

Hey, I tried to use this docker image but faced several things related mainly to performance. I would be grateful for your help or advice.

Mainly using `api28` image, built from the latest `emulator_api_28_x86` branch

* Emulator boot time. I use different types of cloud instances(on GCE), but the average boot time from logs ~ `120000 ms`. Sometimes it follows with `emulator: VERBOSE: System.cpp:1486: Timed out with running command |/opt/android-sdk-linux/platform-tools/adb -s emulator-5554 shell pm revoke com.google.android.googlequicksearchbox android.permission.RECORD_AUDIO |`

Most of the time it also resolves in "System UI not responding" message on the emulator screen which results in failed tests. How can I fix it?

* Are there any scalable examples besides k8s farm? If I just want to create 10-20 emulators of 1 API image and connect CI container to run tests on them? I use simple `docker-compose` with a scale, but emulator start time is still questionable.

* Do you have any CPU\Memory recommendations for host instances? According to `api28` config, one emulator should use 2 cores and 3Gb of memory of the host machine.