I know this question is a month old, but I thought I'd share some help for those coming from Google.
This error pops up because Riot Vanguard (which is known for causing some issues with the emulator) is installed. Riot Vanguard is an anti-cheat system installed along Valorant. So, you have several options:
Keep everything as is
If you dismiss the alert and your emulator works as expected, then you're good to go. I've been developing for Android for a year now with Vanguard installed, without any issues.
Disable the Vanguard service
If something doesn't work as expected, and you don't want to uninstall Valorant, then your next option would be to disable the Vanguard service. For this, you can either go into the Services manager of Windows, or disable it directly from the console. To do the latter, open an elevated CMD and type:
sc config vgc start= disabled
Then, restart your PC, and you're good to go.
This, however, will prevent you from playing Valorant. If you'd like to play, you need to enable Vanguard again, with the following command, and restarting your PC afterwards:
sc config vgc start= system
Uninstall Vanguard
Last option is to uninstall both Valorant and Riot Vanguard. Make sure the Riot Vanguard service is deleted too. You might find it in C:\Program Files\Riot Vanguard\vgc.exe