[BETA] Virtual Device Testing for Android - Custom ADB Script Option

Description of the feature request

Currently the Virtual Device Testing step for Android does not support custom ADB commands.
This is causing issues with the reliability of our Espresso tests as we would like to disable the device animations, as recommended by the documentation:

https://developer.android.com/training/testing/espresso/setup

Set up your test environment
To avoid flakiness, we highly recommend that you turn off system animations on the virtual or physical devices used for testing. On your device, under Settings > Developer options, disable the following 3 settings:

Window animation scale
Transition animation scale
Animator duration scale

Use case / for what or how I would use it

To solve the above issue it would be useful to have the option to run a script after the emulator has booted to allow custom configuration.

We can then run the following to disable the animations:

adb shell settings put global window_animation_scale 0
adb shell settings put global transition_animation_scale 0
adb shell settings put global animator_duration_scale 0