[navigation-material] Fixes crash in BottomSheetNavigator when user goes back

[LluisFelip]

Attempting to address #1750 and #1733.

Although I couldn't reproduce the NullPointerException on BottomSheetNavigator.kt:191, by looking at the code I suggest avoiding the not-null assertion operator on retainedEntry with a let scope function.

[jossiwolf]

Thanks for the PR! We will need a test for this, for which we might need steps to repro. Please let us know if you find any and are able to add a test!

[LluisFelip]

Unfortunately I couldn't find any way of reproducing nor testing it, since it seems to be some sort of race-condition with that retainedEntry val inside that sheetContent Composable function 😞

We're going to try it with real users by replacing this module with the fixed version of it with real users, so we'll be able to assess if it fixes the issue.

Any idea/suggestion on how to test this?

[ianhanniballake]

With the release of Compose Material 1.7.0-alpha04, the Material team has added a new artifact: androidx.compose.material:material-navigation, which fully replaces Accompanist Navigation Material.

As such, we are closing all PRs here on Accompanist.