[path_provider][151823] update supported directories to indicate that Downloads directory now supported on Android.

Author: Sameri11

packages/path_provider/path_provider/README.md

@@ -35,7 +35,7 @@ Directories support by platform:
 | External Storage | ✔️ | ❌ | ❌ | ❌️ | ❌️ |
 | External Cache Directories | ✔️ | ❌ | ❌ | ❌️ | ❌️ |
 | External Storage Directories | ✔️ | ❌ | ❌ | ❌️ | ❌️ |
-| Downloads | ❌ | ✔️ | ✔️ | ✔️ | ✔️ |
+| Downloads | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
 
 ## Testing