Add an optional lineSize parameter to the Activity indicator

**Is your feature request related to a problem? Please describe.**
When using the activity indicator in a large size the default line width doesn't look right for my project (and I imagine for most projects it might be the same)

**Describe the solution you'd like**
Added an optional `lineSize` parameter to the component that lets you specify exactly what size you want.

**Describe alternatives you've considered**
There aren't really any other options.

**Additional context**