Make MAL percentile align with OAL percentile calculation and update Grafana dashboards for OAP observability. (#13546)

Author: wankai123

docs/en/changes/changes.md

@@ -108,6 +108,8 @@
 * BanyanDB: Move data write logic from BanyanDB Java Client to OAP and support observe metrics for write operations.
 * Self Observability: add write latency metrics for BanyanDB and ElasticSearch.
 * Fix the malfunctioning alarm feature of MAL metrics due to unknown metadata in L2 aggregate worker.
+* Make MAL percentile align with OAL percentile calculation.
+* Update Grafana dashboards for OAP observability.
 
 #### UI
 

docs/en/concepts-and-designs/lal.md

@@ -291,7 +291,7 @@ like percentiles.
 
 metrics:
   - name: response_time_percentile
-    exp: http_response_time.sum(['le', 'service', 'instance']).increase('PT5M').histogram().histogram_percentile([50,70,90,99])
+    exp: http_response_time.sum(['le', 'service', 'instance']).increase('PT5M').histogram().histogram_percentile([50,75,90,95,99])
 ```
 
 - `slowSql`