android/ folder is required for non-android plugins #46304
Description
Applications that include non-android plugin packages (e.g a web-only plugin package) are failing to build for Android.
This regressed in #45379 and is fixed in #46282
Unfortunately there have been a few releases between the regression and the fix (as of writing v1.12.10 .. v1.13.0 all have the bug).
To make plugins work in the bad build range we're including a temporary android/ folder in non-android plugins. Once the fix makes it to a stable release plugins can bump the minimal Flutter constraint and cleanup their no-op android folder.
Keeping this open until the fix makes it to a stable release.