Reproduction steps:
1. Create a new project
2. Open project's Build Settings. Observe the "Wait For Managed Debugger" option
3. Create a new script
4. Try to access "Wait For Managed Debugger" option via scripting API

Expected result: "Wait For Managed Debugger" option can be accessed like any other build setting in the EditorUserBuildSettings class
Actual result: There is no public property or method to change this setting in the EditorUserBuildSettings class

Reproducible with: 2018.3.14f1, 2018.4.1f1, 2019.1.4f1, 2019.2.0b4, 2019.3.0a4
Could not test with: 2017.4 ( Wait For Managed Debugger was not present in the Build Settings UI )