add poll module in Android

src/lib.rs

@@ -46,7 +46,7 @@ pub mod mqueue;
 
 pub mod pty;
 
-#[cfg(any(target_os = "linux", target_os = "macos"))]
+#[cfg(any(target_os = "linux", target_os = "android", target_os = "macos"))]
 pub mod poll;
 
 pub mod net;
@@ -96,7 +96,7 @@ pub enum Error {
     /// The operation involved a conversion to Rust's native String type, which failed because the
     /// string did not contain all valid UTF-8.
     InvalidUtf8,
-    /// The operation is not supported by Nix, in this instance either use the libc bindings or 
+    /// The operation is not supported by Nix, in this instance either use the libc bindings or
     /// consult the module documentation to see if there is a more appropriate interface available.
     UnsupportedOperation,
 }