Update Android Docs to reflect minumum version

[zugazagoitia]

Android 15+ should support Jetty 11 (jetty/jetty.project#8912) and therefore (#211/#212) our docs should be updated. Would be good to do a test on Android 15 anyway. If anyone has the OS/VM we would appreciate it. A minimal poc that used to crash can be found at https://github.com/zugazagoitia/jett11-android13-mpoc with both source code and binary.