Fab does not return to original position after snackbar dismiss when using MaterialComponents themes

[vpotvin]

Overview

If your app theme uses a parent of "Theme.MaterialComponents.xxxxxx" then the FAB does not return to its normal position after snackbar dismisses.

I noticed this because I was using a MaterialComponents theme so that I could use the MaterialComponents BottomNavigationView. After much experimenting I narrowed this down as the issue.

Environment (required for bug report)

• OS: Pie
• Device: Pixel 2 Emulator
• Can reproduce on sample app: Yes, if theme is changed

Also saw this behavior on a Samsung S7 Edge running Oreo.

Steps to reproduce (required for bug report)

• Modify sample app so that app theme's parent is "Theme.MaterialComponents.Light.DarkActionBar" make no other changes
• Build app
• Go to Coordinator Activity
• Click Button
• Wait for snackbar to dismiss
• FAB does not move back to expected position

Expected behavior (required for bug report)

• FAB should move back to expected position, but does not.

Known workaround

This can be worked around by not having the app theme extend from a MaterialComponents theme. However this can be annoying as some material components require this theming. This can be worked around by having only those individual components in a layout extend the theme, but again, seems like we should be able to use the MaterialComponents themes since the Androidx FloatingActionButton behaves as desired with these themes.