Set initial value of cooldown setting to true

Bug: 356768397
Test: manual - check that cooldown setting is on,
      turn airplane mode on and off, sending high priority notif
      => notif is suppressed
Flag: com.android.systemui.notification_avalanche_suppression

Change-Id: Ifee08c13d0184e24be65d54d27055f5c3d242727
1 file changed