Add DLP Generation Metadata (#1436)
Add DLP Generation Metadata (#1436)

This PR was generated using Autosynth. :rainbow:

Here's the log from Synthtool:
```
synthtool > Cloning googleapis.
synthtool > Ensuring dependencies.
synthtool > Pulling artman image.
latest: Pulling from googleapis/artman
Digest: sha256:90f9d15e9bad675aeecd586725bce48f5667ffe7d5fc4d1e96d51ff34304815b
Status: Image is up to date for googleapis/artman:latest
synthtool > Running generator for google/privacy/dlp/artman_dlp_v2.yaml.
synthtool > Generated code into /home/kbuilder/.cache/synthtool/googleapis/artman-genfiles/php/google-cloud-dlp-v2.
synthtool > Replaced 'Copyright \\d{4}' in src/V2/Gapic/DlpServiceGapicClient.php.
synthtool > Replaced 'Copyright \\d{4}' in src/V2/DlpServiceClient.php.
synthtool > Replaced 'Copyright \\d{4}' in tests/Unit/V2/DlpServiceClientTest.php.
synthtool > Replaced '@type InspectJobConfig \\$inspectJob\\n' in src/V2/Gapic/DlpServiceGapicClient.php.
synthtool > Replaced '@type RiskAnalysisJobConfig \\$riskJob\\n' in src/V2/Gapic/DlpServiceGapicClient.php.
synthtool > Replaced 'RedactImageRequest_ImageRedactionConfig' in src/V2/Gapic/DlpServiceGapicClient.php.
synthtool > Cleaned up 1 temporary directories.
synthtool > Wrote metadata to synth.metadata.

```
googleapis/google-cloud-php,jdpedrie/google-cloud-php,chingor13/google-cloud-php,jdpedrie/google-cloud-php,googleapis/google-cloud-php,chingor13/google-cloud-php,chingor13/google-cloud-php,googleapis/google-cloud-php,jdpedrie/google-cloud-php