fix(infra): ensure we set az for primary in postgresql (#1973)

<!--- Provide a general summary of your changes in the Title above -->

## Description

<!--- Describe your changes in detail -->

We had an issue where we added HA for `prod`, but the bicep deployment
didn't go through because we need to set the primary az. Setting the
primary az to the one that it was added to when created.

## Related Issue(s)

- #164

## Verification

- [ ] **Your** code builds clean without any errors or warnings
- [ ] Manual testing done (required)
- [ ] Relevant automated test added (if you find this hard, leave it and
we'll help out)

## Documentation

- [ ] Documentation is updated (either in `docs`-directory, Altinnpedia
or a separate linked PR in
[altinn-studio-docs.](https://github.com/Altinn/altinn-studio-docs), if
applicable)

.azure/infrastructure/main.bicep

@@ -56,14 +56,16 @@ param appInsightsSku AppInsightsSku
 
 import { Sku as PostgresSku } from '../modules/postgreSql/create.bicep'
 import { StorageConfiguration as PostgresStorageConfig } from '../modules/postgreSql/create.bicep'
+import { HighAvailabilityConfiguration as PostgresHighAvailabilityConfig } from '../modules/postgreSql/create.bicep'
 
 param postgresConfiguration {
   sku: PostgresSku
   storage: PostgresStorageConfig
   enableIndexTuning: bool
   enableQueryPerformanceInsight: bool
-  enableHighAvailability: bool
+  highAvailability: PostgresHighAvailabilityConfig?
   backupRetentionDays: int
+  availabilityZone: string
 }
 
 import { Sku as ServiceBusSku } from '../modules/serviceBus/main.bicep'
@@ -216,8 +218,9 @@ module postgresql '../modules/postgreSql/create.bicep' = {
     enableQueryPerformanceInsight: postgresConfiguration.enableQueryPerformanceInsight
     subnetId: vnet.outputs.postgresqlSubnetId
     vnetId: vnet.outputs.virtualNetworkId
-    enableHighAvailability: postgresConfiguration.enableHighAvailability
+    highAvailability: postgresConfiguration.?highAvailability
     backupRetentionDays: postgresConfiguration.backupRetentionDays
+    availabilityZone: postgresConfiguration.availabilityZone
     tags: tags
   }
 }

.azure/infrastructure/prod.bicepparam

@@ -36,8 +36,12 @@ param postgresConfiguration = {
   }
   enableIndexTuning: false
   enableQueryPerformanceInsight: false
-  enableHighAvailability: true
+  highAvailability: {
+    mode: 'ZoneRedundant'
+    standbyAvailabilityZone: '2'
+  }
   backupRetentionDays: 32
+  availabilityZone: '3'
 }
 
 param redisSku = {

.azure/infrastructure/staging.bicepparam

@@ -36,8 +36,8 @@ param postgresConfiguration = {
   }
   enableIndexTuning: true
   enableQueryPerformanceInsight: true
-  enableHighAvailability: false
   backupRetentionDays: 7
+  availabilityZone: '2'
 }
 
 param redisSku = {

.azure/infrastructure/test.bicepparam

@@ -36,8 +36,8 @@ param postgresConfiguration = {
   }
   enableIndexTuning: false
   enableQueryPerformanceInsight: true
-  enableHighAvailability: false
   backupRetentionDays: 7
+  availabilityZone: '1'
 }
 
 param redisSku = {

.azure/infrastructure/yt01.bicepparam

@@ -38,8 +38,8 @@ param postgresConfiguration = {
   }
   enableIndexTuning: true
   enableQueryPerformanceInsight: true
-  enableHighAvailability: false
   backupRetentionDays: 7
+  availabilityZone: '1'
 }
 
 param redisSku = {

.azure/modules/postgreSql/create.bicep

@@ -52,10 +52,19 @@ param enableIndexTuning bool
 @description('The name of the Application Insights workspace')
 param appInsightWorkspaceName string
 
-@description('Enable high availability')
-param enableHighAvailability bool
+@export()
+type HighAvailabilityConfiguration = {
+  mode: 'ZoneRedundant' | 'SameZone' | 'Disabled'
+  standbyAvailabilityZone: string
+}
+
+@description('High availability configuration for the PostgreSQL server')
+param highAvailability HighAvailabilityConfiguration?
 
-@description('The number of days to retain backups. If not specified, the default value of 7 days will be used.')
+@description('The availability zone for the PostgreSQL primary server')
+param availabilityZone string
+
+@description('The number of days to retain backups.')
 @minValue(7)
 @maxValue(35)
 param backupRetentionDays int
@@ -94,11 +103,6 @@ module privateDnsZone '../privateDnsZone/main.bicep' = {
   }
 }
 
-var highAvailabilityConfig = enableHighAvailability ? {
-  mode: 'ZoneRedundant'
-  standbyAvailabilityZone: '2'
-} : null
-
 resource postgres 'Microsoft.DBforPostgreSQL/flexibleServers@2024-08-01' = {
   name: postgresServerName
   location: location
@@ -123,7 +127,8 @@ resource postgres 'Microsoft.DBforPostgreSQL/flexibleServers@2024-08-01' = {
       delegatedSubnetResourceId: subnetId
       privateDnsZoneArmResourceId: privateDnsZone.outputs.id
     }
-    highAvailability: highAvailabilityConfig
+    availabilityZone: availabilityZone
+    highAvailability: highAvailability
   }
   sku: sku
   resource database 'databases' = {