Ignore issue #16671 test on android

Seems to be blocking forever

Author: sfackler

src/test/run-pass/issue-16671.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-android seems to block forever
+
 #![forbid(warnings)]
 
 // Pretty printing tests complain about `use std::predule::*`