Prevent crashes on Web

[yousif-bugsnag]

Goal

Prevent apps from crashing on web platform:

• Adds a platform check around the usage of expo-secure-store to get/set the device id (which causes a crash on web). This fixes the crash reported in #183.
• Replaces usage of Constants.platform (which is undefined on web) with the React Native Platform API

Design

Although Web isn't officially supported, this should at least prevent the app from crashing. However this means that device ids will no longer be reported on web, so user stability scores will not work.

Testing

• Relied on existing unit and CI tests to ensure that device IDs are still generated and persisted on Android and iOS
• Manually tested on web

[giaset]

If you want to support (at least some form of) device ID on web, I ended up doing this: https://github.com/bugsnag/bugsnag-expo/issues/183#issuecomment-2148448003

[yousif-bugsnag]

Hi @giaset, thanks for sharing that patch.

Seems sensible enough, however we don't currently support Expo on web, and it's not a platform we test against - so although this PR should prevent the reported crash, we won't be adding web-specific functionality to the library at this time.