Gate bitdrift integration (#7088)

* Move Statsig init call earlier

* Gate Bitdrift init call

* Remove IS_TEST env constant

* Mock statsig

index.js

@@ -5,9 +5,8 @@ import {LogBox} from 'react-native'
 import {registerRootComponent} from 'expo'
 
 import App from '#/App'
-import {IS_TEST} from '#/env'
 
-if (IS_TEST) {
+if (process.env.NODE_ENV === 'test') {
   LogBox.ignoreAllLogs() // suppress all logs in tests
 } else {
   LogBox.ignoreLogs(['Require cycle:']) // suppress require-cycle warnings, it's fine