azuredevops_build_definition - Support first run flag

[xuzhang3]

All Submissions:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My code follows the code style of this project.
• I ran lint checks locally prior to submission.
• Have you checked to ensure there aren't other open PRs for the same update/change?

What about the current behavior has changed?

Issue Number: #862

=== RUN   TestAccBuildDefinition_DataSource
=== PAUSE TestAccBuildDefinition_DataSource
=== RUN   TestAccBuildDefinition_with_path_DataSource
=== PAUSE TestAccBuildDefinition_with_path_DataSource
=== RUN   TestAccBuildDefinition_Basic
=== PAUSE TestAccBuildDefinition_Basic
=== RUN   TestAccBuildDefinition_PathUpdate
=== PAUSE TestAccBuildDefinition_PathUpdate
=== RUN   TestAccBuildDefinition_WithVariables
=== CONT  TestAccBuildDefinition_DataSource
=== CONT  TestAccBuildDefinition_PathUpdate
=== CONT  TestAccBuildDefinition_Basic
=== CONT  TestAccBuildDefinition_with_path_DataSource
=== CONT  TestAccBuildDefinition_Schedules
=== CONT  TestAccBuildDefinition_WithVariables
--- PASS: TestAccBuildDefinition_with_path_DataSource (72.00s)
--- PASS: TestAccBuildDefinition_Schedules (83.95s)
--- PASS: TestAccBuildDefinition_DataSource (85.38s)
--- PASS: TestAccBuildDefinition_Basic (88.03s)
--- PASS: TestAccBuildDefinition_PathUpdate (124.87s)
--- PASS: TestAccBuildDefinition_WithVariables (134.52s)
PASS
ok      github.com/microsoft/terraform-provider-azuredevops/azuredevops/internal/acceptancetests        144.518s

Does this introduce a change to go.mod, go.sum or vendor/?

• Yes
• No

Does this introduce a breaking change?

• Yes
• No

Any relevant logs, error output, etc?

(If it’s long, please paste to https://ghostbin.com/ and insert the link here.)

Other information