chore(linux): Fix API check if lines got removed in .symbols file

If lines got removed in the .symbols file we won't find the current
version number in the .symbols file. This change fixes the expectations.

Also, if a major API change happens during the Alpha cycle we don't expect
another API version increment if one already happened since we released
the stable version.

This change also adds some unit tests for the new functionality. These
can be run manually and won't run during CI builds.

Fixes #10453.