CompareDistributionSignatures task is used to compare Native platform
libraries contents against a previous version.
Under the hood, it runs the klib tool to get a library contents. But it
didn't check the exit code, so if klib tool failed, the task could
mistakenly indicate that there are no differences in platform libs.
Fix this by checking the klib tool exit code and failing if it is not
zero.
Svyatoslav Scherbina
4da8b0850e