fix(Android, Tabs): expose tab item testID as viewIdResourceName

[mackbrowne]

Description

Closes #4496.

A bottom tab item's testID is written to the view's tag property only:

// when matching view by id, espresso driver seems to look for tag property
findTabItemView(menuItem.itemId)?.tag = tabsScreen.tabBarItemTestID

As the comment says, that works for Espresso. But UiAutomator-based drivers — Maestro and Appium — match on AccessibilityNodeInfo.getViewIdResourceName() (exposed as resource-id) and never read the view tag. For them the id is invisible, and a selector silently matches nothing rather than failing loudly, which reads as a flaky tap.

This is inconsistent with the rest of React Native. ReactAccessibilityDelegate does info.viewIdResourceName = testId for every ordinary view, which is why id selectors work everywhere else in an RN app on Android but stop working on native tab items specifically.

Worth noting the intent behind the prop: the JS-side counterpart, expo/expo#47472, added testID to NativeTabs.Trigger explicitly "so native tabs can be matched in end-to-end tests". On Android that currently only holds for Espresso.

Changes

• TabsHostA11yCoordinator.setA11yPropertiesToTabItem now also sets viewIdResourceName on the tab item's accessibility node, via a AccessibilityDelegateCompat.
• The existing tag assignment is kept, so Espresso is unaffected.
• super.onInitializeAccessibilityNodeInfo is called first, so Material's own node population — including the contentDescription and the "tab, N of M" announcement — is preserved.
• The delegate reads tabsScreen.tabBarItemTestID at node-init time rather than capturing it, so a prop update is reflected without reinstalling the delegate.

No public API change, and no visual change, so the visual documentation section is omitted.

Test plan

Verified on a Pixel 8 emulator (API 34) against react-native-screens 4.26.2 applied as a patch, with expo-router 57.0.11 unstable-native-tabs and Maestro 2.6.0. The same change against main's shape is what this PR contains; ktlint 1.3.0 (matching android/spotless.gradle) reports clean on the modified file.

Minimal example:

import { NativeTabs } from 'expo-router/unstable-native-tabs';

export default function Layout() {
  return (
    <NativeTabs>
      <NativeTabs.Trigger name="index" testID="tab-home">
        <NativeTabs.Trigger.Label>Home</NativeTabs.Trigger.Label>
        <NativeTabs.Trigger.Icon md="home" />
      </NativeTabs.Trigger>
      <NativeTabs.Trigger name="search" testID="tab-search">
        <NativeTabs.Trigger.Label>Search</NativeTabs.Trigger.Label>
        <NativeTabs.Trigger.Icon md="search" />
      </NativeTabs.Trigger>
    </NativeTabs>
  );
}

Inspect the accessibility tree, no test framework required:

adb shell uiautomator dump /sdcard/ui.xml && adb shell cat /sdcard/ui.xml | tr '>' '>\n' | grep navigation_bar_item

	tab item nodes
before	no resource-id
after	resource-id="tab-home" / resource-id="tab-search"

In both cases content-desc still holds the label and selected still tracks the active tab, so the screen-reader behaviour is unchanged. Equivalently, a Maestro step - tapOn: { id: "tab-search" } matches nothing before the change and taps the tab after it; in a real suite all four tabs of an app shell flow now tap by id.

I have not been able to run the repo's own Android e2e suite locally, so I would appreciate CI confirming that. Happy to add a Test*.tsx example under apps/src/tests if you would like one for this.

Checklist

• Included code example that can be used to test this change.
• For visual changes, included screenshots / GIFs / recordings documenting the change. (no visual change)
• For API changes, updated relevant public types. (no API change)
• Ensured that CI passes (cannot run the Android e2e suite locally; relying on CI)