fix(android): do not cancel PendingIntent before setAlarmClock on reschedule

Remove existingPendingIntent.cancel() in the "cancel existing alarm before
rescheduling" block. The cached PendingIntent can be the same instance passed
to setAlarmClock; cancelling it can prevent the new alarm from firing. Keep
only alarmManager.cancel(existingPendingIntent) to clear the previous alarm.

android/src/main/java/com/timesafari/dailynotification/NotifyReceiver.kt

@@ -321,7 +321,8 @@ class NotifyReceiver : BroadcastReceiver() {
                 if (existingPendingIntent != null) {
                     Log.w(SCHEDULE_TAG, "Cancelling existing alarm before rescheduling: requestCode=$requestCode, scheduleId=$stableScheduleId, source=$source")
                     alarmManager.cancel(existingPendingIntent)
-                    existingPendingIntent.cancel()
+                    // Do not call existingPendingIntent.cancel(): the cached PendingIntent may be the same
+                    // object we pass to setAlarmClock below; cancelling it can prevent the new alarm from firing.
                 }
             } catch (e: Exception) {
                 Log.w(SCHEDULE_TAG, "Failed to cancel existing alarm before scheduling: $stableScheduleId", e)