Unhide AccessibilityWindowInfo#refresh for window state checks

Make AccessibilityWindowInfo#refresh public. This allows
accessibility clients to check and refresh the cached window
state to avoid accessing stale windows.

See go/android-a11y-api-proposal-unhide-accessibilitywindowinfo-refresh

Flag: android.view.accessibility.enable_refresh_window_info
Bug: 405371739 (FR)
Bug: 415818857
Test: atest AccessibilityWindowReportingTest#testRefreshWindowInfo
Change-Id: Ie63bbeb35cf678a797a9a94f824486cc32014a46