Bring back custom action inkwell colors for post bottom sheet

[micahmo]

Pull Request Description

This PR fixes a "breaking change" (I put that in quotes because it's really just cosmetic 😊) introduced by the post bottom sheet refactor in #1567, which is that we lost the colored inkwells for the quick actions. This is such a minor thing, but it was introduced by @CTalvio back in the day and I really like it, so I wanted to bring it back. Note that this still works fine in the post page itself, as well as the bottom sheet for comments.

P.S. @hjiangsu are you planning on a doing a similar refactor for comments any time soon? Right now the bottom sheets look and act differently which causes a slightly disjointed user experience.

Issue Being Fixed

Issue Number: N/A

Screenshots / Recordings

qemu-system-x86_64_nIzKDB1iMs.mp4

Checklist

• If a new package was added, did you ensure it uses an appropriate license and is actively maintained?
• Did you use localized strings (and added appropriate descriptions) where applicable?
• Did you add semanticLabels where applicable for accessibility?

[hjiangsu]

P.S. @hjiangsu are you planning on a doing a similar refactor for comments any time soon? Right now the bottom sheets look and act differently which causes a slightly disjointed user experience.

Definitely, this is on my to-do list before the general release of v0.6.0 (in addition to some more comment moderation tools if I can get around to them)!

The changes look good - I was planning on releasing v0.6.0-2 nightly in a bit, so I'll hold off on merging this in until then!