fix build, android

Signed-off-by: dignow <linlong1265@gmail.com>

src/keyboard.rs

@@ -214,6 +214,7 @@ static mut IS_0X021D_DOWN: bool = false;
 #[cfg(target_os = "macos")]
 static mut IS_LEFT_OPTION_DOWN: bool = false;
 
+#[cfg(not(any(target_os = "android", target_os = "ios")))]
 fn get_keyboard_mode() -> String {
     #[cfg(not(any(feature = "flutter", feature = "cli")))]
     if let Some(session) = CUR_SESSION.lock().unwrap().as_ref() {