[native] Fix Android ChatThreadListItem to dim when held

Summary: I noticed that when I depress ChatThreadListItems on Android, they didn't react at all. Turns out that applying a background-color inside the Button component leads to the TouchableNativeFeedback on Android getting drawn over

Test Plan: I tested iOS and Android, in dark mode and light mode. I tested press down on each

Reviewers: palys-swm

Reviewed By: palys-swm

Subscribers: KatPo, zrebcu411, Adrian, atul, subnub

Differential Revision: https://phabricator.ashoat.com/D910