Enable continuous backup for AllVersionsAndDeletes change feed tests

Add enableContinuousBackup parameter to test-resources.bicep to configure
continuous backup policy when needed. Add a new account configuration in
live-platform-matrix.json for AllVersionsAndDeletes change feed tests that
enables continuous backup.

This fixes the live tests for PR #4706 that require continuous backup to
be enabled for the AllVersionsAndDeletes change feed mode to function properly.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: f2f63ad0-37fe-4d65-a2a3-0329ae6cb793

Author: NaluTripician

sdk/cosmos/live-platform-matrix.json

@@ -52,6 +52,9 @@
         },
         "Session MultiRegion GatewayV2": {
           "ArmTemplateParameters": "@{ defaultConsistencyLevel = 'Session'; enableMultipleRegions = $true; testCategory = 'gateway_v2_multi_region' }"
+        },
+        "Session SingleRegion ChangeFeed AllVersionsAndDeletes": {
+          "ArmTemplateParameters": "@{ defaultConsistencyLevel = 'Session'; enableContinuousBackup = $true; testCategory = 'all_versions_and_deletes' }"
         }
       }
     }

sdk/cosmos/test-resources.bicep

@@ -9,6 +9,9 @@ param enableMultipleWriteLocations bool = false
 @description('Dictates which tests run for this resource')
 param testCategory string = 'emulator'
 
+@description('Flag to enable continuous backup mode')
+param enableContinuousBackup bool = false
+
 @description('Default Cosmosdb Account level consistency')
 param defaultConsistencyLevel string = 'Session'
 
@@ -74,6 +77,19 @@ resource cosmosAccount 'Microsoft.DocumentDB/databaseAccounts@2023-04-15' = {
         {name: 'EnableNoSQLVectorSearch'}, {name: 'EnableNoSQLFullTextSearch'}
     ]
     locations: locationsConfiguration
+    backupPolicy: (enableContinuousBackup ? {
+      type: 'Continuous'
+      continuousTierPolicy: {
+        state: 'On'
+      }
+    } : {
+      type: 'Periodic'
+      periodicModeProperties: {
+        backupIntervalInMinutes: 240
+        backupRetentionIntervalInHours: 8
+        backupStorageRedundancy: 'Geo'
+      }
+    })
   }
 }