Increase default timeout to mitigate 504 error of Proxy Module

### Describe the feature

Increased the default timeout of Nginx instance from 75s to 300s, and increase the default ALB idle time from 60s to 300s. 

### Use Case

With this change, you can export a report from OpenSearch 5 times larger than before. 

### Proposed Solution

_No response_

### Other Information

_No response_

### Solution version used

v2.1.1