For an emulator that mimics a Pixel 5 Device with Google APIs and ARM architecture (for an M1/M2 Macbook):

1. List All System Images Available for Download: sdkmanager --list | grep system-images

2. Download Image: sdkmanager --install "system-images;android-33;google_apis;arm64-v8a"

3. Create Emulator: echo "no" | avdmanager --verbose create avd --force --name "pixel_5" --package "system-images;android-33;google_apis;arm64-v8a" --tag "google_apis" --abi "arm64-v8a" --device "pixel_5"

Note: To check which devices you can create from the command line, run avdmanager list deviceand pass in the device name as the value of --device, e.g. --device "pixel_5" at the end of the command on step 3.

For generic skin emulator with default apis (without google apis):

1. List All System Images Available for Download: sdkmanager --list | grep system-images

2. Download Image: sdkmanager --install "system-images;android-31;default;x86_64"

3. Create Emulator: echo "no" | avdmanager --verbose create avd --force --name "generic_api31_emulator" --package "system-images;android-31;default;x86_64" --tag "default" --abi "x86_64"

   If you do not use the --device flag, I recommend adding these lines to: ~/.android/avd/generic_10.avd/config.ini or else your emulator will have a very low resolution. 
   Note: Increasing resolution will decrease performance on CI.
   
   skin.name=1080x1920        # proper screen size for emulator
   hw.lcd.density=480
   hw.keyboard=yes            # enables keys from your laptop to be sent to the emulator
   
   If you cannot do this, you can still pass -skin 1080x1920 as an argument when starting the emulator. 
   
   Keep in mind, you can also pass the --device flag and use a device name from the avdmanager list device command which          should also set a default resolution because it will inherit the set of properties of that "device" in the config.ini.
   

4. Run Emulator: emulator @generic_api31_emulator & or emulator @pixel_5 &

See: Google Documentation on Start the emulator from the command line for more info See: https://developer.android.com/studio/command-line/avdmanager for more info on AVDManager. See; https://developer.android.com/studio/command-line/sdkmanager for more info on SDKManager.

Add aliases to your ~/.zshrc or ~/.bashrc to run the emulators with parameters more easily.

alias generic_api31_emulator='emulator @generic_api31_emulator -no-boot-anim -netdelay none -no-snapshot -wipe-data -skin 768x1280 &'

alias pixel_5 ='emulator @pixel_5 -no-boot-anim -netdelay none -no-snapshot -wipe-data &'

You can pass the -read-only parameter when starting up an emulator emulator @pixel_5 -read-only to run multiple devices at the same time.

1. aosp_atd and google_atd system images are only available on x86 and ARM architecture at API level 30. sdkmanager --list | grep atd See also: https://android-developers.googleblog.com/2021/10/whats-new-in-scalable-automated-testing.html

  system-images;android-30;aosp_atd;arm64-v8a                                              | 1            | AOSP ATD ARM 64 v8a System Image
  system-images;android-30;aosp_atd;x86                                                    | 1            | AOSP ATD Intel x86 Atom System Image
  system-images;android-30;google_atd;arm64-v8a                                            | 1            | Google APIs ATD ARM 64 v8a System Image
  system-images;android-30;google_atd;x86                                                  | 1            | Google APIs ATD Intel x86 Atom System Image

2. avdmanager list device is great to figure out which emulators you can create