[MaterialContainerTransform] RecyclerView content is gone during transition when LinearLayoutManager.recycleChildrenOnDetach = true

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**Description:** I'm using `MaterialContainerTransform` in a fragment transition.

I see that `RecyclerView#onDetachedFromWindow()` gets called immediately as soon as the transition starts unlike `onDestroyView()` that waits for the transition to end. For performance improvement, I'm setting `LinearLayoutManager#recycleChildrenOnDetach` to `true`. This flag makes `LinearLayoutManager#onDetachedFromWindow()` clear the views in the RecyclerView causing the screen to turn blank when the transition starts. ([ref](https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:recyclerview/recyclerview/src/main/java/androidx/recyclerview/widget/LinearLayoutManager.java;l=233?q=linearlayoutmanager))

The real issue is that `RecyclerView#onDetachedFromWindow()` doesn't wait for the transition to complete. In a regular fragment transition without `MaterialContainerTransform`, this method gets called only after the transition is completed.

**Source code:** https://github.com/mkano9/material-container-transform-recycleChildrenOnDetach/tree/master
See [FirstFragment](https://github.com/mkano9/material-container-transform-recycleChildrenOnDetach/blob/master/app/src/main/java/com/example/materialcontainertransformplayground/FirstFragment.kt#L59)

Video: https://user-images.githubusercontent.com/57272551/105796603-0c143d80-5f44-11eb-994b-a2dc8196cdd2.mp4

**Android API version:** 30

**Material Library version:** 1.3.0-rc01

**Device:** Pixel 3 XL

Start by running the linked reproduction project and reading app/src/main/java/com/example/materialcontainertransformplayground/FirstFragment.kt around the reported transition. Trace the MaterialContainerTransform fragment transition alongside RecyclerView#onDetachedFromWindow() and LinearLayoutManager#recycleChildrenOnDetach; done means the RecyclerView content remains visible throughout the transition with that flag enabled.

Written by the indexing model from the issue text.