[Doc]: Code doesn't return all operations for all databases in SQL Pool, instead asks for single database name

### Description

https://docs.microsoft.com/en-us/powershell/module/az.sql/get-azsqldatabaseactivity?view=azps-8.1.0&tryIt=true&source=docs#code-try-1

Code doesn't return all operations for all databases in SQL Pool, instead asks for single database name.

Open the linked Get-AzSqlDatabaseActivity documentation and inspect the Code Try 1 example. Verify whether the example requests a single database name instead of showing operations for all databases in a SQL Pool, then update the documentation so the example and its behavior are accurately described.

Written by the indexing model from the issue text.