Cherry-pick #11366 to 7.x: packetbeat: Enable setting promiscuous mode automatically

[michalpristas]

Cherry-pick of PR #11366 to 7.x branch. Original message:

This PR tries to enable promiscuous mode when using af_packet.

Few things to mention

• when it fails it does not panic just logs the failure, mostly because of and backward compatibility
• on exit: it resets promisc mode to whatever it was before
• when any is used it does not set the mode to promiscuous - following pcap

Fixes #700

Manual testing guide:

Basic check:

• check promisc mode is disabled on your device (e.g. ip link show {device}) (look for PROMISC keyword)
• enable promisc mode by including packetbeat.interfaces.auto_promisc_mode: true into packetbeat config
• check promisc mode is enabled (e.g. ip link show {device})
• stop packetbeat
• check promisc mode is disabled (e.g. ip link show {device})

Already on promisc check:

• enable promisc mode on your devide (e.g. ifconfig {device} promisc or ip link set {device} promisc on
• enable promisc mode by including packetbeat.interfaces.auto_promisc_mode: true into packetbeat config
• check promisc mode is enabled (e.g. ip link show {device})
• stop packetbeat
• check promisc mode is still enabled (e.g. ip link show {device})