Regenerate pubsub client

[yoshi-automation]

This PR was generated using Autosynth. 🌈

Here's the log from Synthtool:

synthtool > Executing /tmpfs/src/git/autosynth/working_repo/google-cloud-clients/google-cloud-pubsub/synth.py.
synthtool > Ensuring dependencies.
synthtool > Pulling artman image.
latest: Pulling from googleapis/artman
Digest: sha256:38a27ba6245f96c3e86df7acb2ebcc33b4f186d9e475efe2d64303aec3d4e0ea
Status: Image is up to date for googleapis/artman:latest
synthtool > Cloning googleapis.
synthtool > Running generator for google/pubsub/artman_pubsub.yaml.
synthtool > Generated code into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/java.
synthtool > Replaced 'setMaxInboundMessageSize\\(Integer.MAX_VALUE\\)' in src/main/java/com/google/cloud/pubsub/v1/stub/SubscriberStubSettings.java.
synthtool > Running java formatter on 45 files
synthtool > Running java formatter on 2 files
synthtool > Running java formatter on 89 files
synthtool > Cleaned up 0 temporary directories.
synthtool > Wrote metadata to synth.metadata.