* fix: reset stuck start lock on system Always-on VPN restart
When Android restarts CoreVpnService for Always-on VPN (via VpnService.SERVICE_INTERFACE
or null intent), a stuck isStartingLock from a killed process prevents tryLockStart() from
succeeding, causing an immediate return without setupVpnService().
Fix: Reset stuck start lock via unlockStart() on system-initiated VPN start/restart,
allowing setupVpnService() to establish the TUN interface. If setup fails during system
start, return START_STICKY to keep the service alive for OS reconnection.
Also accept LOCKED_BOOT_COMPLETED and MY_PACKAGE_REPLACED in BootReceiver.
* Update BootReceiver.kt
* Update CoreVpnService.kt
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Co-authored-by: 2dust <31833384+2dust@users.noreply.github.com>
