Unity: export android project, then build it

Builder.cs

using System;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Threading;
using UnityEditor;
using UnityEngine;
using Debug = UnityEngine.Debug;

public class Builder
{
    [MenuItem("Tools/Test")]
    public static void Test()
    {        
        var options = new BuildPlayerOptions
        {
            locationPathName = Env.AndroidProjectPath,
            target = BuildTarget.Android,
            options = BuildOptions.AcceptExternalModificationsToPlayer
        };
        BuildPipeline.BuildPlayer(options);
        
        GradleHelper.Run(Env.AndroidProjectPath, "assembleDebug");
    }
    
    [MenuItem("Tools/AssetDatabase Refresh")]
    public static void AssetDatabaseRefresh()
    {
        AssetDatabase.Refresh();
    }
}

public static class Env
{
    private static string GetUnityPath(params string[] fileSystemEntries)
    {
        // example: C:\Program Files\Unity\Hub\Editor\2019.3.2f1\Editor
        var unityDir = AppDomain.CurrentDomain.BaseDirectory;
        return Path.GetFullPath(unityDir + "/" + string.Join("/", fileSystemEntries));
    }

    private static string JavaPath => GetEditorPref("JdkPath");

    public static string JavaExePath => Path.Combine(JavaPath, "bin", "java");

    private static string GradlePath =>
        GetUnityPath("Data", "PlaybackEngines", "AndroidPlayer", "Tools", "gradle", "lib");

    public static string GradleExePath =>
        Directory.EnumerateFileSystemEntries(GradlePath, "gradle-launcher-*.jar").First();
    
    // example: C:/Users/Venom/projects/New 2019 Unity Proj/New Unity Project/Assets
    private static string ProjectPath => Path.GetFullPath(Path.Combine(Application.dataPath, ".."));

    public static string AndroidProjectPath => Path.Combine(ProjectPath, "Build");

    private static string GetEditorPref(string key)
    {
        if (!EditorPrefs.HasKey(key))
        {
            throw new Exception($"Environment: {key} not set. Probably you can set it from Edit -> Preferences -> External Tools");
        }

        return EditorPrefs.GetString(key);
    }
}

public static class ProcessRunner
{
    public static int DoProcess(string workingDir, string fileName, string[] arguments)
    {
        return DoProcess(workingDir, fileName, string.Join(" ", arguments));
    }
    
    public static int DoProcess(string workingDir, string fileName, string arguments)
    {
        Debug.Log($"ProcessRunner: executing: {fileName} {arguments}\n\tWorking directory: {workingDir}");

        int exitCode;
        using (var process = new Process
        {
            StartInfo =
            {
                WorkingDirectory = workingDir,
                WindowStyle = ProcessWindowStyle.Hidden,
                CreateNoWindow = true,
                UseShellExecute = false,
                FileName = fileName,
                Arguments = arguments,
                RedirectStandardError = true,
                RedirectStandardOutput = true
            },
            EnableRaisingEvents = true
        })
        {
            using (var outputWaitHandle = new AutoResetEvent(false))
            using (var errorWaitHandle = new AutoResetEvent(false))
            {
                process.OutputDataReceived += (sender, args) =>
                {
                    // ReSharper disable once AccessToDisposedClosure
                    if (args.Data != null) Debug.Log(args.Data);
                    else outputWaitHandle.Set();
                };
                process.ErrorDataReceived += (sender, args) =>
                {
                    // ReSharper disable once AccessToDisposedClosure
                    if (args.Data != null) Debug.LogError(args.Data);
                    else errorWaitHandle.Set();
                };

                process.Start();
                process.BeginOutputReadLine();
                process.BeginErrorReadLine();
                // process.WaitForExit causes hang when redirecting output e.g. with '> someFile.txt'
                // So using wait handles instead
                // https://stackoverflow.com/questions/139593/processstartinfo-hanging-on-waitforexit-why
                WaitHandle.WaitAll(new WaitHandle[] { outputWaitHandle, errorWaitHandle });
    
                exitCode = process.ExitCode;
                Debug.Log($"ProcessRunner: process exit code {exitCode} in {(process.ExitTime - process.StartTime).TotalSeconds.ToString(CultureInfo.InvariantCulture)} sec ({fileName} {arguments})");
            }
        }
        return exitCode;
    }
}

public static class GradleHelper
{
    public static void Run(string androidProjectPath, string task)
    {
        // example: -classpath "C:\Program Files\Unity\Hub\Editor\2019.3.2f1\Editor\Data\PlaybackEngines\AndroidPlayer\Tools\gradle\lib\gradle-launcher-5.1.1.jar" org.gradle.launcher.GradleMain "-Dorg.gradle.jvmargs=-Xmx4096m" "assembleRelease"
        var args = new[]
        {
            "-classpath", $"\"{Env.GradleExePath}\"",
            "org.gradle.launcher.GradleMain",
            "-Dorg.gradle.jvmargs=-Xmx4096m",
            task
        };

        ProcessRunner.DoProcess(androidProjectPath, Env.JavaExePath, args);
    }
}