React Native Windows 0.62.0-preview.3

• a7cbd081 Removed the ref count work around from classes derived from ReactApplications (vmorozov@microsoft.com)
• cd2a3a9a Promote awaitable DispatchQueue callback to member field (julio.rocha@microsoft.com)
• 1ef8caf1 Treat yes the same as y in template overwrite prompt (acoates@microsoft.com)
• d3a37578 Disable CxxFrameHandler4 (ngerlem@microsoft.com)
• 3e084881 Ensure InitializeCore is run before app code (acoates@microsoft.com)