PublicIncludePaths array in a 4.20 plugin looks for the include path in relation to the Engine instead of the plugin

A plugin created in 4.19 automatically includes an entry for the plugin's Public directory in the PublicIncludePaths array in the Plugin.Build.cs file. Plugins created in 4.20 no longer automatically add this entry. When a 4.19 project that includes a plugin is upgraded to 4.20, a build warning no occurs stating that the included directory does not exist. However, the path in the warning is in relation to the root Engine directory instead of the root plugin directory. The same warning appears if a new include path is added to the PublicIncludePaths array.

1. Create a new basic code project in 4.19.
2. Add a new plugin to the project named "MyPlugin" (tested using a Third Party Library plugin and a Blueprint Function Library plugin).
3. Upgrade the project to 4.20 by creating a copy of the project.
4. Open the 4.20 project solution in Visual Studio.
5. Build the project in Visual Studio.

RESULT:
The build produces a warning similar to the following: warning : Referenced directory 'D:\Source\UnrealEngine-4.20.0-release\Engine\Source\MyPlugin\Public' does not exist.

EXPECTED:
The build completes without any warning.