Ubuntu 14.04 LTS uses GNOME 3.10. adwaita-icon-theme was not introduced until GNOME 3.14. Before that point, the theme was named gnome-icon-theme. Therefore, I recommend you install gnome-icon-theme-full.
Or you could opt in to the Windows Insider Program. With build 14936 and higher, Ubuntu 16.04 LTS is used for new Bash on Ubuntu on Windows installs. I believe you need to opt in to the Fast Ring currently for that but after installing the latest build, you can choose the Slow Ring if you don't want frequent updates.
Ubuntu 14.04 LTS uses GNOME 3.10. adwaita-icon-theme was not introduced until GNOME 3.14. Before that point, the theme was named gnome-icon-theme. Therefore, I recommend you install gnome-icon- theme-full.
Or you could opt in to the Windows Insider Program. With build 14936 and higher, Ubuntu 16.04 LTS is used for new Bash on Ubuntu on Windows installs. I believe you need to opt in to the Fast Ring currently for that but after installing the latest build, you can choose the Slow Ring if you don't want frequent updates.