stop converting timeouts to/from minutes

[danawillow]

Noticed this again while working on hashicorp/terraform-provider-google#3954, and figured this is as good a time as any to actually fix it.

Release Note Template for Downstream PRs (will be copied)

* all: fixed bug where timeouts specified in units other than minutes were getting incorrectly rounded. Also fixed several instances of timeout values being used from the wrong method.

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 115 files changed, 404 insertions(+), 403 deletions(-))
Terraform Beta: Diff ( 137 files changed, 482 insertions(+), 477 deletions(-))
TF Conversion: Diff ( 2 files changed, 6 insertions(+), 5 deletions(-))

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 117 files changed, 408 insertions(+), 406 deletions(-))
Terraform Beta: Diff ( 139 files changed, 486 insertions(+), 480 deletions(-))
TF Conversion: Diff ( 2 files changed, 6 insertions(+), 5 deletions(-))