Support multi-process scope sync

### Description

Currently if the Android SDK is used in an multi-process app, the scopes are not synchronized between processes, meaning breadcrumbs/tags/contexts from one process will not show up for errors from another. We should probably introduce a flag to make this opt-in, and to make it work we can do one of the following:

1. Communicate between processes using `IBinder` through a [bound service](https://developer.android.com/develop/background-work/services#CreatingBoundService) and package data as Parcelable. Here's a good example on implementing IPC: https://github.com/perihanmirkelam/IPC-Examples
2. Persist the scope data to disk from both processes and when an error occurs in any of them, use the persisted data in favour of what's currently in-memory. We already do persist the data for ANRs, so it could be as simple as replacing our MainEventProcessor and DefaultAndroidEventProcessor with a new one that reads the data from disk (use [AnrV2EventProcessor](https://github.com/getsentry/sentry-java/blob/main/sentry-android-core/src/main/java/io/sentry/android/core/AnrV2EventProcessor.java) as prior art).