The new plugin uses a newer version of animalsniffer, allows overriding
the animalsniffer version used, and has up-to-date handling. The
up-to-date handling cuts fully incremental parallel build times in half,
from 5.5s to 2.7s.
The previous plugin was supposed to be verifying tests. However, either
it wasn't verifying them or its verification was broken.
It converts Google Auth Library Credentials to CallCredentials, and
supersedes ClientAuthInterceptor, which is now deprecated.
Also swaps out the ClientAuthInterceptor implementation.
Caveat: This in fact changes ClientAuthInterceptor's behavior. Before
this change, if multiple ClientAuthInterceptors were attached, their
effects would be additive. After this change, only the last executed one
would take effect, and it would also overwrite the CallCredentials set
in CallOptions. We don't think it's an issue, since other languages also
only allow one call credentials to be attached to an RPC.