v0.2.0 of my_device_info

Privacy-aware, typed Android and iOS device diagnostics in one call, with an opt-in app-scoped identifier. Changelog excerpt: - Add typed `DeviceInfoSnapshot`, `OperatingSystemInfo`, and `DevicePlatform`APIs. - Add `MyDeviceInfo.getInfo()`to read device diagnostics with one native call. - Keep the app-scoped identifier opt-in and redact it from `toJson()`by default. - Add model identifier,…