[iOS][Engine] Fix view removal process for AutofillContextAction.cancel (#160653)

Original PR flutter/engine#57209

---

The `removeFromSuperview` in the `hideTextInput` method was triggering
the save password, so I changed it to `cleanUpViewHierarchy`.

fix flutter/flutter#145681

sample app code

https://github.com/koji-1009/autofill_cancel_issue

before


https://github.com/user-attachments/assets/c380538b-6783-4706-9a09-4db1c3b761df

after


https://github.com/user-attachments/assets/b6654b80-f383-408d-9820-6fe53279ce14

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Author: koji-1009

engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.mm

@@ -2685,8 +2685,11 @@ - (void)hideTextInput {
   [self removeEnableFlutterTextInputViewAccessibilityTimer];
   _activeView.accessibilityEnabled = NO;
   [_activeView resignFirstResponder];
-  [_activeView removeFromSuperview];
-  [_inputHider removeFromSuperview];
+  // Removes the focus from the `_activeView` (UIView<UITextInput>)
+  // when the user stops typing (keyboard is hidden).
+  // For more details, refer to the discussion at:
+  // https://github.com/flutter/engine/pull/57209#discussion_r1905942577
+  [self cleanUpViewHierarchy:YES clearText:YES delayRemoval:NO];
 }
 
 - (void)triggerAutofillSave:(BOOL)saveEntries {

engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputPluginTest.mm

@@ -2718,6 +2718,27 @@ - (void)testInitialActiveViewCantAccessTextInputDelegate {
   XCTAssertNil(textInputPlugin.activeView.textInputDelegate);
 }
 
+- (void)testAutoFillDoesNotTriggerOnHideButTriggersOnCommit {
+  // Regression test for https://github.com/flutter/flutter/issues/145681.
+  NSMutableDictionary* configuration = self.mutableTemplateCopy;
+  [configuration setValue:@{
+    @"uniqueIdentifier" : @"field1",
+    @"hints" : @[ UITextContentTypePassword ],
+    @"editingValue" : @{@"text" : @""}
+  }
+                   forKey:@"autofill"];
+  [configuration setValue:@[ [configuration copy] ] forKey:@"fields"];
+
+  [self setClientId:123 configuration:configuration];
+  XCTAssertEqual(self.viewsVisibleToAutofill.count, 1ul);
+
+  [self setTextInputHide];
+  // Before the fix in https://github.com/flutter/flutter/pull/160653, it was 0ul.
+  XCTAssertEqual(self.viewsVisibleToAutofill.count, 1ul);
+
+  [self commitAutofillContextAndVerify];
+}
+
 #pragma mark - Accessibility - Tests
 
 - (void)testUITextInputAccessibilityNotHiddenWhenShowed {