chore: generate GAPIC metadata JSON file (#63)

This PR was generated using Autosynth. 🌈

Synth log will be available here:
https://source.cloud.google.com/results/invocations/cb56ba31-8af5-4a2d-bb02-4d94fe4706d8/targets

- [ ] To automatically regenerate this PR, check this box.

PiperOrigin-RevId: 345596855
Source-Link: googleapis/googleapis@d189e87

Author: yoshi-automation