Improve reliability of OOM test
Improve reliability of OOM test

Capturing the battery and orientation values in the initial creation of the
BugsnagSystemState object ensures they will be there when the app is terminated
to simulate an OOM.

The test was sometimes failing because BugsnagSystemState queues up
asynchronous writes in the background and these do not always have time
to complete when running the test scenario.

bugsnag/bugsnag-cocoa,bugsnag/bugsnag-cocoa,bugsnag/bugsnag-cocoa,bugsnag/bugsnag-cocoa