Fix building for Android, enable tlmgr updates (#896)

* fix(os/unix): cannot find `SkipStep` while building for android

ERROR: cannot find function, tuple struct or tuple variant `SkipStep`

Disable updating gnome extensions for Android.

Signed-off-by: Aditya Alok <dev.aditya.alok@gmail.com>

* feat: enable `tlmgr` updates for android

Signed-off-by: Aditya Alok <dev.aditya.alok@gmail.com>

src/steps/os/unix.rs

@@ -135,7 +135,7 @@ pub fn run_fish_plug(ctx: &ExecutionContext) -> Result<()> {
     ctx.run_type().execute(&fish).args(&["-c", "plug update"]).check_run()
 }
 
-#[cfg(not(target_os = "macos"))]
+#[cfg(not(any(target_os = "android", target_os = "macos")))]
 pub fn upgrade_gnome_extensions(ctx: &ExecutionContext) -> Result<()> {
     let gdbus = require("gdbus")?;
     require_option(