Gaussian filtering uses aggressive settings when Filtering enum is set to Advanced

Jira twin of: https://fogbugz.unity3d.com/f/cases/1362188/

Steps to reproduce

1. Open an existing Unity project, or create a new one
2. Navigate to Window > Rendering > Lighting
3. Click on the New Lighting Settings button
4. Navigate to Filtering, and set that enum to Advanced
5. Notice, that Gaussian filtering settings are overly aggressive

Notes

• Suggest changing each Gaussian kernel size to 1 texel. This will match the behavior in Auto filtering preset

Current settings

[Internal link]

Suggested settings

[Internal link]