[MaterialDatePicker] Talkback does not announce initially selected date as "selected"

Nobody has claimed this yet.

Description: An initially selected date (e.g., a date set using MaterialDatePickerBuilder.datePicker().setSelection()) is not announced as "selected" when using Talkback. It is necessary for the user to interactively select a date at which point "selected" will be prepended to the announcement of the date. After that, Talkback will correctly announce the selected date.

- Expected behavior: Regardless of whether the date is initially selected or interactively selected, Talkback should announce "selected" when swiping to the selected date.

- Source code:

Add the following to an Activity's "onCreate" to build and show a date picker dialog :

var datePicker = MaterialDatePicker.Builder.datePicker().setSelection(Date().time).build()
.show(supportFragmentManager,"")

Note that when initially swiping to the selected date, it will not be announced as selected (see attached video).

- Android API version: 34

- Device: Pixel 5

- Material Library Version : com.google.android.material:material:1.9.0

https://github.com/material-components/material-components-android/assets/26826628/7a31c145-97e1-4a65-a354-473404d6dd6a

Reproduce the issue using MaterialDatePicker.Builder.datePicker().setSelection(Date().time) on Android API 34 with TalkBack enabled. Trace the MaterialDatePicker date-selection accessibility behavior, then verify that an initially selected date is announced as selected and that interactive selection remains correct.

Written by the indexing model from the issue text.