This change will now allow for customizing the port number when running the metro server. The environment variable `RCT_METRO_PORT` can now be set when executing commands like `make run-ios`, `make run ios-device`, and `make run-android`. Though, it should be noted that `make clean` may need to be ran before attempting to set or change `RCT_METRO_PORT` since the react-native app will have statically built code that references the value of RCT_METRO_PORT from compile time and not runtime.
fixes#18888
## Summary
`make run-android` was sometimes flaky because we used to send metro to background via `nohup` and then bring it back to foreground after we read metro logs.
Now we do not send metro to background. We first wait for a successful build.
we then install the app on the simulator. After this is done we give command to sleep until metro server has started, Once metro server has started we open the installed app.
In this workflow the command to open the installed app goes in background and metro stays in foreground.
The new workflow should now be less flaky.
## Review notes
`make run-clojure`
`make run-android` OR `make run-ios` should just work
#### Platforms
- Android
- iOS
Sean Hagstrom
Siddarth Kumar