Misc UI tweaks

- Reduced padding around online indicator to allow for better use of space on Contact Cards
- Fixed bg color on introduction drawer to surfaceVariant everywhere (previously the bg color was not uniform throughout).
- Made introduction drawer header "X" button actually line up with contact list (was off by a few pixels before)
- Introduction drawer now centers profile pictures and alias'.
- ProfilePictures and MessageCounters now use 1px borders to better match briar android.
- Remove ConversationList top and bottom padding.
- Bump font size of ExposedDropDownMenu to typography.body1 to match everything else.
- Add auto-formatting rule that fixed ktlint problems I was running into.