Fixes TextInput shaking when typing Chinese (#28805)

Summary:
Fixes #28488.

## Changelog

[iOS] [Fixed] - Fixes TextInput shaking when typing Chinese
Pull Request resolved: #28805

Test Plan: Demo see #28488.

Differential Revision: D21376803

Pulled By: shergin

fbshipit-source-id: b1fe6cc5f67d42ef98a6c12b8ab9990feac0e2a7

Author: zhongwuzw

Libraries/Text/TextInput/Multiline/RCTUITextView.m

@@ -104,6 +104,10 @@ - (void)setPlaceholderColor:(UIColor *)placeholderColor
 
 - (void)setDefaultTextAttributes:(NSDictionary<NSAttributedStringKey, id> *)defaultTextAttributes
 {
+  if ([_defaultTextAttributes isEqualToDictionary:defaultTextAttributes]) {
+    return;
+  }
+
   _defaultTextAttributes = defaultTextAttributes;
   self.typingAttributes = defaultTextAttributes;
   [self _updatePlaceholder];

Libraries/Text/TextInput/Singleline/RCTUITextField.m

@@ -68,6 +68,10 @@ - (void)setPlaceholderColor:(UIColor *)placeholderColor
 
 - (void)setDefaultTextAttributes:(NSDictionary<NSAttributedStringKey, id> *)defaultTextAttributes
 {
+  if ([_defaultTextAttributes isEqualToDictionary:defaultTextAttributes]) {
+    return;
+  }
+
   _defaultTextAttributes = defaultTextAttributes;
   [super setDefaultTextAttributes:defaultTextAttributes];
   [self _updatePlaceholder];