[TextField][A11y] Replace deprecated announceForAccessibility with accessibility live region

PiperOrigin-RevId: 762446288

Author: Material Design Team

lib/java/com/google/android/material/textfield/TextInputLayout.java

@@ -2453,14 +2453,26 @@ public void setPlaceholderText(@Nullable final CharSequence placeholderText) {
     if (placeholderTextView == null) {
       placeholderTextView = new AppCompatTextView(getContext());
       placeholderTextView.setId(R.id.textinput_placeholder);
-      placeholderTextView.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_NO);
+      placeholderTextView.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
+      placeholderTextView.setAccessibilityLiveRegion(ViewCompat.ACCESSIBILITY_LIVE_REGION_POLITE);
 
       placeholderFadeIn = createPlaceholderFadeTransition();
       placeholderFadeIn.setStartDelay(PLACEHOLDER_START_DELAY);
       placeholderFadeOut = createPlaceholderFadeTransition();
 
       setPlaceholderTextAppearance(placeholderTextAppearance);
       setPlaceholderTextColor(placeholderTextColor);
+
+      ViewCompat.setAccessibilityDelegate(
+          placeholderTextView,
+          new AccessibilityDelegateCompat() {
+            @Override
+            public void onInitializeAccessibilityNodeInfo(
+                @NonNull View host, @NonNull AccessibilityNodeInfoCompat info) {
+              super.onInitializeAccessibilityNodeInfo(host, info);
+              info.setVisibleToUser(false);
+            }
+          });
     }
 
     // If placeholder text is null, disable placeholder.
@@ -2531,7 +2543,6 @@ private void showPlaceholderText() {
       TransitionManager.beginDelayedTransition(inputFrame, placeholderFadeIn);
       placeholderTextView.setVisibility(VISIBLE);
       placeholderTextView.bringToFront();
-      announceForAccessibility(placeholderText);
     }
   }