Add support for Config Sync enabled field in ConfigManagement Fleet-level default config

[haiyanmeng]

Add support for Config Sync enabled field in ConfigManagement Fleet-level default config. Note this field is already supported in Pantheon UI and gcloud.

The Config Sync enabled field was added in
GoogleCloudPlatform/declarative-resource-client-library@c3703a0.

Release Note Template for Downstream PRs (will be copied)

gkehub: added `config_sync.enabled` field to ConfigManagement `fleet_default_member_config`

[github-actions]

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[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.

google provider: Diff ( 3 files changed, 29 insertions(+), 2 deletions(-))
google-beta provider: Diff ( 3 files changed, 29 insertions(+), 2 deletions(-))
terraform-google-conversion: Diff ( 1 file changed, 11 insertions(+))

[modular-magician]

Tests analytics

Total tests: 26
Passed tests: 13
Skipped tests: 10
Affected tests: 0

Click here to see the affected service packages

• gkehub2

$\textcolor{green}{\textsf{All tests passed!}}$

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[github-actions]

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