Drop Animal Sniffer in favor of building with a newer JDK using the release flag

[axelfontaine]

Currently the SDK includes a dependency on Animal Sniffer to ensure to no APIs that were introduced post Java 8 are used. This can be replaced by the javac --release argument when building with newer JDKs and the annotations dependency can be removed.

As documented on https://www.mojohaus.org/animal-sniffer/

[BenWhitehead]

Thanks for the recommendation. This is something that is on our radar, and it being prioritised along with all of the other Google Cloud Java Libraries.

[axelfontaine]

I may have missed it, but I don't believe you are even using the annotations anywhere in storage, so that dependency can be safely dropped right now.