Add copyright headers to files in .teamcity/

[SarahFrench]

Addresses these automated PRs:

• [COMPLIANCE] Add Copyright and License Headers hashicorp/terraform-provider-google#15196
• [COMPLIANCE] Add Copyright and License Headers hashicorp/terraform-provider-google-beta#5907

Also this PR changes a misleading comment about what days of the week the build configurations are triggered on

Release Note Template for Downstream PRs (will be copied)

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

Terraform GA: Diff ( 12 files changed, 62 insertions(+), 1 deletion(-))
Terraform Beta: Diff ( 12 files changed, 62 insertions(+), 1 deletion(-))
TF Conversion: Diff ( 2 files changed, 3 insertions(+), 3 deletions(-))

[zli82016]

LGTM. Thanks.

[SarahFrench]

Just rebased to solve some merge conflicts. I'm going to save merging this PR until after other PRs have been merged, as I don't want to create merge conflicts in more important PRs!

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

Terraform GA: Diff ( 10 files changed, 51 insertions(+))
Terraform Beta: Diff ( 10 files changed, 51 insertions(+))
TF Conversion: Diff ( 2 files changed, 3 insertions(+), 3 deletions(-))

[SarahFrench]

I'm going to save merging this PR until after other PRs have been merged, as I don't want to create merge conflicts in more important PRs!

Not a problem currently, so merging.