Bump google_project timeout

[rileykarson]

and add docs to indicate they're user configurable.

Fixes hashicorp/terraform-provider-google#6852

Release Note Template for Downstream PRs (will be copied)

resourcemanager: bumped `google_project` timeout defaults to 10 minutes (from 4)

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 2 files changed, 13 insertions(+), 4 deletions(-))
Terraform Beta: Diff ( 2 files changed, 13 insertions(+), 4 deletions(-))

[modular-magician]

I have triggered VCR tests based on this PR's diffs. See the results here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=135954"

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccEndpointsService_basic|TestAccFolderIamAuditConfig_multiple You can view the result here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=135956"