As it turns out after a long research let me list out some options you have here to run react native app on an EC2 machine or Amazon workspace.
AWS Device Farms
AWS device farms in a managed service which test your apps against real devices, its the best option if budget is not a problem as AWS device farms is an expensive service (0.17$ per minute) at the time of writing.
AWS Device Farms official page
Genymotion Cloud
Gennymotion cloud is a cheaper alternative to AWS device farms it deploys on amazon ec2 and available on aws marketplace as AMI.
Gennymotion cloud AMI
Rovello Systems
Rovello Systems is owned by Oracle and it supports nested virtualization you can signup in Ravello and then you will be able to run the android emulator in your ec2.
Rovello Systems
Expo Client
Expo Client is the easiest way to test your react native app on android and ios, just install the expo client app and cli and you can test it on the real device at no cost.
Expo client
Remote ADB
Another workaround is to use remote ADB however for this you have to use a rooted android phone, roms like lineage os provide this option as an inbuilt option.
USB Redirect
Last and just another workaround is to redirect USB to EC2 server, many remote desktop clients support to redirect the USB to a remote computer so you can connect the Android device in your local computer and redirect it to ec2 server.
if you know any other method please mention it in comment box I'm open for discussion