Fix config file and document typo for ttl (#5087) (#5088)

docs/en/setup/backend/ttl.md

@@ -7,7 +7,7 @@ You have following settings for different types.
 ```yaml
     # Set a timeout on metrics data. After the timeout has expired, the metrics data will automatically be deleted.
     recordDataTTL: ${SW_CORE_RECORD_DATA_TTL:3} # Unit is day
-    metricsDataTTL: ${SW_CORE_RECORD_DATA_TTL:7} # Unit is day
+    metricsDataTTL: ${SW_CORE_METRICS_DATA_TTL:7} # Unit is day
 ```
 
 - `recordDataTTL` affects **Record** data, including tracing and alarm.

oap-server/server-bootstrap/src/main/resources/application.yml

@@ -66,7 +66,7 @@ core:
     enableDataKeeperExecutor: ${SW_CORE_ENABLE_DATA_KEEPER_EXECUTOR:true} # Turn it off then automatically metrics data delete will be close.
     dataKeeperExecutePeriod: ${SW_CORE_DATA_KEEPER_EXECUTE_PERIOD:5} # How often the data keeper executor runs periodically, unit is minute
     recordDataTTL: ${SW_CORE_RECORD_DATA_TTL:3} # Unit is day
-    metricsDataTTL: ${SW_CORE_RECORD_DATA_TTL:7} # Unit is day
+    metricsDataTTL: ${SW_CORE_METRICS_DATA_TTL:7} # Unit is day
     # Cache metric data for 1 minute to reduce database queries, and if the OAP cluster changes within that minute,
     # the metrics may not be accurate within that minute.
     enableDatabaseSession: ${SW_CORE_ENABLE_DATABASE_SESSION:true}