Make database version required for google_sql_database_instance

[shuyama1]

Fixes hashicorp/terraform-provider-google#5212

If this PR is for Terraform, I acknowledge that I have:

• Searched through the issue tracker for an open issue that this either resolves or contributes to, commented on it to claim it, and written "fixes {url}" or "part of {url}" in this PR description. If there were no relevant open issues, I opened one and commented that I would like to work on it (not necessary for very small changes).
• Generated Terraform, and ran make test and make lint to ensure it passes unit and linter tests.
• Ensured that all new fields I added that can be set by a user appear in at least one example (for generated resources) or third_party test (for handwritten resources or update tests).
• Ran relevant acceptance tests (If the acceptance tests do not yet pass or you are unable to run them, please let your reviewer know).
• Read the Release Notes Guide before writing my release note below.

Release Note Template for Downstream PRs (will be copied)

sql: changed the `database_version` field to `Required` in `google_sql_database_instance` resource

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 16 files changed, 128 insertions(+), 91 deletions(-))
Terraform Beta: Diff ( 16 files changed, 131 insertions(+), 93 deletions(-))
TF OiCS: Diff ( 2 files changed, 6 insertions(+), 4 deletions(-))

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccDataSourceGoogleSQLCaCerts_basic|TestAccDatasourceGoogleServiceNetworkingPeeredDnsDomain_basic|TestAccCloudRunService_cloudRunServiceSqlExample|TestAccContainerCluster_withAddons|TestAccContainerCluster_withWorkloadIdentityConfigDeprecation|TestAccContainerCluster_withWorkloadIdentityConfig|TestAccServiceNetworkingPeeredDNSDomain_basic|TestAccSQLDatabase_sqlDatabaseBasicExample|TestAccSqlDatabaseInstance_basicSecondGen|TestAccSqlDatabaseInstance_basicMSSQL|TestAccSqlDatabaseInstance_settings_basic|TestAccSqlDatabaseInstance_settings_deletionProtection|TestAccSqlDatabaseInstance_slave|TestAccSqlDatabaseInstance_maintenance|TestAccSqlDatabaseInstance_diskspecs|TestAccSqlDatabaseInstance_settings_upgrade|TestAccSqlDatabaseInstance_settingsDowngrade|TestAccSqlDatabaseInstance_multipleOperations|TestAccSqlDatabaseInstance_authNets|TestAccSqlDatabaseInstance_basic_with_user_labels|TestAccSqlDatabaseInstance_withPrivateNetwork|TestAccSqlClientCert_postgres|TestAccSqlDatabase_basic|TestAccSqlDatabase_update|TestAccSqlClientCert_mysql You can view the result here: https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=211185

[modular-magician]

Tests failed during RECORDING mode: TestAccSqlClientCert_postgres Please fix these to complete your PR

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 16 files changed, 127 insertions(+), 90 deletions(-))
Terraform Beta: Diff ( 17 files changed, 131 insertions(+), 93 deletions(-))
TF OiCS: Diff ( 2 files changed, 6 insertions(+), 4 deletions(-))

[shuyama1]

/gcbrun

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 16 files changed, 127 insertions(+), 90 deletions(-))
Terraform Beta: Diff ( 17 files changed, 131 insertions(+), 93 deletions(-))
TF OiCS: Diff ( 2 files changed, 6 insertions(+), 4 deletions(-))

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccContainerNodePool_withGPU|TestAccServiceNetworkingPeeredDNSDomain_basic|TestAccSqlUser_postgresIAM You can view the result here: https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=211341

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 16 files changed, 127 insertions(+), 90 deletions(-))
Terraform Beta: Diff ( 17 files changed, 132 insertions(+), 93 deletions(-))
TF OiCS: Diff ( 2 files changed, 6 insertions(+), 4 deletions(-))

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccComposerEnvironment_basic|TestAccComposerEnvironment_update|TestAccComposerEnvironment_ComposerV2|TestAccComputeBackendBucket_backendBucketFullExample|TestAccComputeBackendBucket_withCdnPolicy|TestAccContainerNodePool_withWorkloadIdentityConfig|TestAccDataprocCluster_withServiceAcc|TestAccProject_migrateParent|TestAccSqlUser_postgresIAM You can view the result here: https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=212555