android: qr scanner: add emoji to clipboard string

The string is not translated and might not be accessible for non-english
speakers, even though its relatively self-explanatory i think adding
this emoji makes it more accessible.

contrib/ban_unicode.py

@@ -29,7 +29,7 @@ EXCLUDE_EXTENSIONS = {
 UNICODE_WHITELIST = {
     "💬", "🗯", "⚠", chr(0xfe0f), "✓", "▷", "▽", "…", "•", "█", "™", "≈",
     "á", "é", "’",
-    "│", "─", "└", "├",
+    "│", "─", "└", "├", "📋",
 }
 
 exit_code = 0