Report internal SDK errors to bugsnag

[fractalwrench]

Goal

Rather than sending minimal error reports, the SDK now reports internal SDK errors to bugsnag
instead in a way that does not route them to customer dashboards. A minimal report is generated
which is not altered in callbacks and is not cached to disk.

Changeset

• Updated ErrorStore to inform a delegate of an exception, rather than creating an error from the filename
• Removed sending of minimal error reports and associated tests
• Updated onErrorReadFailure() to add metadata to a generated error about the file being read, and then report an internal error to bugsnag
• Added reportInternalBugsnagError(), which sends an error report that is picked up by Bugsnag's internal monitoring
• Send minimal app/device data in internal error reports, along with some metadata about the exception
• Avoid running callbacks, caching internal error reports to disk, or reattempting delivery

Note: in order to alter the headers on a per-request basis, DefaultDelivery must be used as the delivery mechanism, as otherwise we'd need to make a breaking change to the delivery signature. If a user has specified a custom Delivery mechanism we're unable to send these reports. This API limitation has already been rectified in the immutable config work where we can specify different headers for individual requests

Tests

• Manually inspected payload
• Sent payload to dashboard (by temporarily altering changeset to add an API key)
• Added a mazerunner scenario to verify internal error reports are sent

[kattrali]

Looks good and works as expected in my testing. 👍 For future proofing, I think the test could better reflect the case(s) we want to handle. A good rule would be that we (generally) shouldn't need to call an internal API from a functional test, though I recognize that there isn't a direct way to flush reports at the moment.

[fractalwrench]

I've updated the mazerunner scenario so that it now creates an empty file in the reports directory, which will trigger an internal error report.

[bengourley]

I tested the following permutations and all exhibited the expected outcomes:

Case	Outcome	Expected
Empty file in the bugsnag-errors directory	Sent java.io.EOFException to internal dashboard	✅
Invalid JSON file in bugsnag-errors directory	Sent android.util.MalformedJsonException to internal dashboard	✅
Valid JSON with no errors in bugsnag-errors directory	Sent java.io.IOException to internal dashboard	✅
Missing stacktrace	Sent the stack-less exception to normal dashboard	✅
Errors stored on disk from previous version 4.18.0	Sent errors to normal dashboard successfully	✅