Android/README.me: mention Java version

Author: vstinner

Platforms/Android/README.md

@@ -30,7 +30,8 @@ any packages it needs.
 The script also requires the following commands to be on the `PATH`:
 
 * `curl`
-* `java` (or set the `JAVA_HOME` environment variable)
+* `java` (or set the `JAVA_HOME` environment variable).
+  Java versions 17 and 21 are supported.
 
 ## Building