Installation fails when trying to install Unity AndroidPlayer on macOS
I managed to defeat the issue by installing the required packages from the Unity Hub, instead of manually downloading & installing.
Start Unity -> click Installs
-> reveal Add Modules
by clicking the vertical 3 dots and select the modules required by clicking on the checkboxes.
I managed to install Android support using the full Unity3D installer and making sure that the Android support is selected. Could be a specific problem with the AndroidPlayer installation package.