[DatePicker][A11y] Replace the deprecated announcement API used for month navigation

PiperOrigin-RevId: 760547908

Author: Material Design Team

lib/java/com/google/android/material/datepicker/MaterialCalendar.java

@@ -473,14 +473,6 @@ public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
             int currentMonthPosition = monthsPagerAdapter.getPosition(moveToMonth);
             updateNavigationButtonsEnabled(currentMonthPosition);
           }
-
-          @Override
-          public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
-            if (newState == RecyclerView.SCROLL_STATE_IDLE) {
-              CharSequence announcementText = monthDropSelect.getText();
-              recyclerView.announceForAccessibility(announcementText);
-            }
-          }
         });
 
     monthDropSelect.setOnClickListener(

lib/java/com/google/android/material/datepicker/res/layout/mtrl_calendar_month_navigation.xml

@@ -30,17 +30,18 @@
     android:layout_weight="1">
 
     <com.google.android.material.button.MaterialButton
-      style="?attr/materialCalendarYearNavigationButton"
       android:id="@+id/month_navigation_fragment_toggle"
+      style="?attr/materialCalendarYearNavigationButton"
       android:layout_width="wrap_content"
       android:layout_height="@dimen/mtrl_calendar_navigation_height"
       android:layout_gravity="start"
+      android:accessibilityLiveRegion="polite"
       android:gravity="center_vertical|start"
       android:insetBottom="0dp"
       android:insetTop="0dp"
       app:icon="@drawable/material_ic_menu_arrow_down_black_24dp"
       app:iconGravity="textEnd"
-      app:iconPadding="4dp"/>
+      app:iconPadding="4dp" />
 
   </FrameLayout>