'adb pair' by mdns instance name.

Bug: 152886765

Test: Turn on wireless debugging > "Pair with Pairing Code". On client,
> adb pair <mdns_instance>

Change-Id: I8f15c3ea17f3ac02205064f64aca0167bf5d2ad5
diff --git a/adb/adb_wifi.h b/adb/adb_wifi.h
index 5113c15..42f414b 100644
--- a/adb/adb_wifi.h
+++ b/adb/adb_wifi.h
@@ -42,6 +42,7 @@
 };
 
 std::optional<MdnsInfo> mdns_get_connect_service_info(std::string_view name);
+std::optional<MdnsInfo> mdns_get_pairing_service_info(std::string_view name);
 
 #else  // !ADB_HOST