tns run/devices fails (w/ fix info)

Environment

• CLI: 5.3.1

Describe the bug
After upgrading to the latest version of the Android Studio Emulator, Images, SDK; tns devices fails with the following error:

Connected devices & emulators
Searching for devices...
Cannot find connected devices. Reconnect any connected devices, verify that your system recognizes them, and run this command again.

tns run android fails with:

Searching for devices...
Cannot find connected devices.
Emulator start failed with: No emulator image available for device identifier 'undefined'.
To list currently connected devices and verify that the specified identifier exists, run 'tns device'.
To list available emulator images, run 'tns device <Platform> --available-devices'.

Doing a tns devices --log full gives me this:

spawn: /home/.../Android/Sdk/platform-tools/adb "devices"
Error while checking for devices. TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received type undefined
    at assertPath (path.js:39:11)
    at Object.join (path.js:1155:7)
    at AndroidVirtualDeviceService.<anonymous> (/usr/local/lib/node_modules/nativescript/lib/common/mobile/android/android-virtual-device-service.js:65:38)
    at Generator.next (<anonymous>)
    at fulfilled (/usr/local/lib/node_modules/nativescript/lib/common/mobile/android/android-virtual-device-service.js:10:58)
    at process._tickCallback (internal/process/next_tick.js:68:7)
Cannot find connected devices. Reconnect any connected devices, verify that your system recognizes them, and run this command again.
(node:14038) [DEP0079] DeprecationWarning: Custom inspection function on Objects via .inspect() is deprecated

Key line being: android-virtual-device-service.js:65

tns doctor shows no issues.
adb devices -- does show the running emulators properly...

To Reproduce
Upgrade to the latest sdk, tools:

Expected behavior
It actually works. 😀

Additional context
Setting the
ANDROID_AVD_HOME & ANDROID_SDK_ROOT fixes the issue. From what I can gather ANDROID_HOME is now depreciated... So this might need to be an added error in TNS doctor; and a warning here instead of throwing an error that is unhelpful...

ANDROID_SDK_ROOT should be the same value as ANDROID_HOME
ANDROID_AVD_HOME on my Linux machine ends up being /home/<USER_NAME>/.android/avd/
On mac, it will probably be /Users/<USER_NAME>/.android/avd/