sendCallNotification returned after the iOS VoIP branch, so a user signed in
on both an iPhone (ios-voip token) and an Android phone only got the call on
iOS — the Android invite was never sent, so a swiped-away Android phone never
rang (confirmed on-device: only type=cancel reached Android, never
type=invite, since sendCallCancel does fan out to all platforms). Now send to
iOS VoIP AND Android FCM, and only fall back to the banner when no native
device was waked. Server-only; no app rebuild.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>