* FIRSecureStorage -> GULKeychainStorage: renamed and moved to GoogleUtilities * FIS updated to GULKeychainStorage * Run ./scripts/style.sh * Headers order * GULKeychainUtils API docs * GULKeychainStorage: require Keychain service name
* FIS - use shared user defaults if `accessGroup` is set. * Use `FIROptions.appGroupID` to set keychain `accessGroup` * ./scripts/style.sh