Refactor: Update task container and thumbnail dimming progress

This commit updates the mechanism for dimming task containers and thumbnails in the recents view. These changes simplify the dimming logic and improve the performance of the recents view. It reduces the usage of Flows to propagate progress and animation states through the views and view models.

The following changes were made:

- The `TaskThumbnailViewModel` no longer provides a dimming level.
- The `TaskViewModel` now provides a `tintAmount` flow that represents the dimming level for a task.
- The `TaskContainer` and `TaskThumbnailView` now use the `tintAmount` flow to update their dimming level.
- The `TaskContainer` now also updates the dimming level based on the menu open progress.
- The `TaskThumbnailView` now uses a `MultiPropertyFactory` to manage the dimming level, allowing it to be controlled by both the tint amount and the menu open progress.

Bug: 390581380
Doc: go/launcher-overview-unified-taskviewmodel
Flag: com.android.launcher3.enable_refactor_task_thumbnail
Test: OverviewImageTest
Test: TaskViewModelTest
Test: TaskThumbnailViewModelImplTest
Test: TaskThumbnailViewScreenshotTest
Change-Id: I04d5dee534d56857b977d7f3ed6d4eda9f93be45