Fix retention window for RPC (#972)

Author: psheth9

docs/data/rpc/admin-guide.mdx

@@ -164,7 +164,7 @@ For all deployments, we recommend at least 10GB of disk/storage space.
 | --- | --- | --- | --- | --- | --- |
 | Soroban RPC | 2 vCPU | 4-8 GB | 30 GB persistent volume >= 3K IOPS | [c5.large] | [n4-highcpu-2] |
 
-_\* Assuming a 30-day retention window for data storage._
+_\* Assuming a 7-day retention window for data storage._
 
 ### Kubernetes With Helm