chore(OsLogin): support common protos in owlbot.py and update generated files

[JoeWang1127]

OsLogin depends on unversioned protobuf message classes in the namespace
Google\Cloud\OsLogin\Common (such as PosixAccount and SshPublicKey),
which are generated from google/cloud/oslogin/common/common.proto.

Previously, the Bazelbot/Owlbot generation pipeline was copying Common proto files: googleapis-gen bundles all PHP proto files (Common and V1) together under google/cloud/oslogin/v1/google-cloud-oslogin-v1-php/proto/src/. Because Common and V1 are siblings in staging, synthtool's _find_copy_target algorithm visits Common/ first, fails to match version_string="v1", and aborts the search, skipping both Common and V1 proto copying.

This change updates OsLogin/owlbot.py to:

• Move Common proto and metadata directories out of v1 staging prior
  to calling owlbot_main() in the legacy pipeline.
• Explicitly copy common-protos via php.owlbot_copy_version() if staged
  separately by Librarian.

Also updates the generated Common and V1 proto classes and metadata to the latest Protobuf 33.2 compiler output (using public RepeatedField imports, typed array docblocks, and hex-escaped descriptor strings).

The change to PHP code is generated by running Owlbot copy:

docker run --rm --user $(id -u):$(id -g) -v .:/repo -w /repo -v ../googleapis-gen:/googleapis-gen --env HOME=/tmp gcr.io/cloud-devrel-public-resources/owlbot-cli:latest copy-code  --source-repo=/googleapis-gen --config-file=OsLogin/.OwlBot.yaml

docker run --rm --user $(id -u):$(id -g) -v $(pwd):/repo -w /repo   --env HOME=/tmp   gcr.io/cloud-devrel-public-resources/owlbot-php:latest