[BUG] Modifying body wrapper #opensearch-dashboards-body causing global behavior changes

[kavilla]

• https://github.com/opensearch-project/dashboards-observability/blob/main/public/components/event_analytics/explorer/explorer.scss#L7
• https://github.com/opensearch-project/dashboards-observability/blob/main/public/components/metrics/index.scss#L7

Modify behavior throughout the entire app as it this style ID wraps the entire body of the application.

One example is the Advanced Settings.

• Go to Advanced Settings
• Make a change
• Notice how you must scroll to the very bottom of the page to find the Unsaved Changes bar

The expected behavior is the Unsaved Changes overlays at the bottom of the window.