Granite's storagebar not styled in dark mode

[fabiozaramella]

What Happened

I just notice that granite's storage bars are not styled at all or not styled properly when using dark style.

Expected Behavior

It should be styled accordingly, assuring the correct degree of contrast.

Steps to Reproduce

1. Set system style to Dark Style
2. Open Files and click open a file/folder properties window or check style in Granite's Demo app (I haven't double checked with it)
3. Notice the difference in styling with Light/Default Style

Sorry, I can't attach a screenshot at moment currently on mobile.

Platform Information

Full-updated Odin daily with stylesheet from master.