[fix] accessibilityLevel should control semantic tag

Fix #1965

packages/react-native-web/src/modules/AccessibilityUtil/__tests__/propsToAccessibilityComponent-test.js

@@ -24,6 +24,15 @@ describe('modules/AccessibilityUtil/propsToAccessibilityComponent', () => {
     ).toEqual('h3');
   });
 
+  test('when "accessibilityRole" is "heading" and "accessibilityLevel" is set', () => {
+    expect(
+      propsToAccessibilityComponent({
+        accessibilityRole: 'heading',
+        accessibilityLevel: 3
+      })
+    ).toEqual('h3');
+  });
+
   test('when "accessibilityRole" is "label"', () => {
     expect(propsToAccessibilityComponent({ accessibilityRole: 'label' })).toEqual('label');
   });

packages/react-native-web/src/modules/AccessibilityUtil/propsToAccessibilityComponent.js

@@ -46,7 +46,7 @@ const propsToAccessibilityComponent = (props: Object = emptyObject) => {
   const role = propsToAriaRole(props);
   if (role) {
     if (role === 'heading') {
-      const level = props['aria-level'];
+      const level = props.accessibilityLevel || props['aria-level'];
       if (level != null) {
         return `h${level}`;
       }