AndroidBundletoolPath.cs

using System.IO;
using System.Linq;
using UnityEditor;

namespace Kogane
{
    public static class AndroidBundletoolPath
    {
        private static string m_value;

        public static string Value
        {
            get
            {
                if ( !string.IsNullOrWhiteSpace( m_value ) ) return m_value;

                var contentsDirectoryName = EditorApplication.applicationPath.Replace( "Unity.app", "" );
                var toolsDirectoryName    = $"{contentsDirectoryName}PlaybackEngines/AndroidPlayer/Tools";

                m_value = Directory
                        .EnumerateFiles
                        (
                            path: toolsDirectoryName,
                            searchPattern: "bundletool-all-*.jar",
                            searchOption: SearchOption.TopDirectoryOnly
                        )
                        .FirstOrDefault()
                    ;

                return m_value;
            }
        }
    }
}