Steps to reproduce:
1. Create a directory named "xyz" under Sdk/build-tools/ (e.g. C:\\android-sdk\build-tools\xyz)
2. Open any project
3. Open Build Settings window
4. Switch to Android
5. Press Build

Expected result: a project is built without any errors
Actual result: Android build settings window is broken, ArgumentException errors flood the console and/or builds fail with ArgumentException errors

Reproducible with: 2019.2.0a1, 2019.2.0a2, 2019.2.0a3 (d51e0e10f042)
Not reproducible with: 2018.3.3f1, 2019.1.0b1

Notes:
- log attached: error.txt
- tested on Linux and Windows
- any dir name that does not follow the standard SDK version naming (e.g. 23.0.0) will cause the bug to reproduce (e.g. '1', 'a', 'xyz', 'android-Q', etc.)
- in Edit/Preferences/External Tools, enabling "Android SDK Tools Installed with Unity" does not change anything