chore: run the generator, dec 2, 2020

[grant]

Re-runs the generator.

• Updates headers
• Uses string type for 64 bit numbers (uses updated jsonschemas). See https://developers.google.com/protocol-buffers/docs/proto3#json
• Not exactly sure why the longer terms were lingering from before, but shortens longer terms like GoogleEventsCloudCloudbuildV1TimeSpan.

Uses these PRs:

• fix: remove oneof type for 64 bit numbers google-cloudevents#123
• fix: use https with license google-cloudevents#104

[jskeet]

Again, I'd prefer not to merge things that depend on other unmerged/untagged changes, but if we need to do this to unblock things, we can.

[grant]

Again, I'd prefer not to merge things that depend on other unmerged/untagged changes, but if we need to do this to unblock things, we can.

The other changes were merged. I won't merge PRs out of order.