Re-enable checks for MANAGE_IPSEC_TUNNELS

This patch ensures that creation and modification of IPsec tunnels
requires the MANAGE_IPSEC_TUNNELS appop.

Bug: 115685048
Test: IpSecManagerTunnelTest fails without appops set
Change-Id: I6c60a2573ca521717877f36e28a392b0d3b62754