recordLaunch method
Records an app launch and initialises the install timestamp on first run.
Implementation
Future<void> recordLaunch() async {
final prefs = SharedPreferencesAsync();
final now = DateTime.now().millisecondsSinceEpoch;
final firstLaunch = await prefs.getInt(_kFirstLaunchKey);
if (firstLaunch == null) {
await prefs.setInt(_kFirstLaunchKey, now);
}
final count = (await prefs.getInt(_kLaunchCountKey)) ?? 0;
await prefs.setInt(_kLaunchCountKey, count + 1);
}