Disable animations for Android UI tests

build.gradle

# Don't forget to change test runner in app's build.gradle file
...
android {
    ...
    defaultConfig {
        ...
        testInstrumentationRunner "in.bala.TestRunner"
    }
    ...
}

TestRunner.kt

import android.app.Application
import android.content.Context
import android.os.Bundle
import android.provider.Settings.Global.*
import androidx.test.platform.app.InstrumentationRegistry
import androidx.test.runner.AndroidJUnitRunner

class TestRunner : AndroidJUnitRunner() {
    override fun onCreate(arguments: Bundle?) {
        super.onCreate(arguments)
        setAnimations(false)
    }

    override fun finish(resultCode: Int, results: Bundle?) {
        setAnimations(true)
        super.finish(resultCode, results)
    }

    private fun setAnimations(enabled: Boolean) {
        val value = if (enabled) "1.0" else "0.0"
        InstrumentationRegistry.getInstrumentation().uiAutomation.run {
            this.executeShellCommand("settings put global $WINDOW_ANIMATION_SCALE $value")
            this.executeShellCommand("settings put global $TRANSITION_ANIMATION_SCALE $value")
            this.executeShellCommand("settings put global $ANIMATOR_DURATION_SCALE $value")
        }
    }
}