Crashpad added a new WER (Windows Error Reporting) handler which needs
to be manually registered first in the Windows Registry, and then with
the crashpad client.
This WER module is able to capture a wider range of crashes that would otherwise bypass the in-process structured exception handling (SEH) mechanism.

Co-authored-by: Mischan Toosarani-Hausberger <mischan@abovevacant.com>

This adds a bunch more NULL-checks for the outer opaque transaction/_ctx and span types.
Also removes the `span_free` function which was pretty much duplicated with span_decref.

* chore: update libunwindstack-ndk submodule

synced with commit
235e2604e2fa3c1f8f7a68c5e285f9622e741e64

of upstream repo:
https://android.googlesource.com/platform/system/unwinding

here:
getsentry/libunwindstack-ndk#6

* Update changelog

It happens regularly that the android simulator doesn't start (for whatever reason). But by default, that obsolete step runs until the default job timeout of 360 minutes is reached.

When starting successfully, this job step never reaches 6 minutes, so 10 minutes should give it more than enough time (and would still be within the bounds of our typical CI run end-to-end of ~15 mins).