Our custom global variable would be nicer declared as a `const`. `var` doesn't seem to present any advantages here. Functionality-wise the block scope remains the same as the global scope. Semantic-wise it's clear it is global as @emin93 already moved it below imports. Also ib4 wave of ESLint `no-var` adopters (e.g. https://github.com/gabts/eslint-config-react-native-typescript). Further, see: https://eslint.org/docs/rules/no-var#when-not-to-use-it