Since we added to nstat's telegraf plugin the possibility
to collect data from `/proc/net/softnet_stat` regarding
dropped packets and rx_net_action a.k.a time squeeze, we need to enable
it globally on all hosts.

Also grafana dashboard update to include new graphs + added four
new Prometheus alers.

Related-Bug: PROD-21090

Change-Id: I9dfe87bdc8b677a51e3f305dd3c75c7d4cc4e0d4

Change alerts names, severity and descriptions.

Closes-bug: PROD-19718
Change-Id: I238fbcd51cf48389b504ccb531ba9b2bc9dd4be6

Change-Id: I963dbca50f9ce9f7ad4913640e18833039b68992
Partial-Bug: PROD-16264

Change-Id: I87d132ce6473715b0992e561b2855456f24bcb3b

Change-Id: I94f09359f976ccd0f207277da52d20e659b36a69

Change-Id: I456ed02ad54a9b55486b4c4a61c9cebfb8f28613

Change-Id: Ie3f9da382c23148836e4a20ff0f37c3929e062cf

This change adds the Telegraf configuration to collect swap metrics, the
associated Prometheus alarms and graphs to the Grafana dashboard.

Change-Id: I3595fd0b8cab06215c620642da69dd29c398396a

Change-Id: I008818853c2058746be08365283b949177efa254
Depends-On: I3c3c569a013aff8c3ab8e46cffb93a60d74ddf09

Change-Id: I80193afad1842f67967d1bab164f049078e3cd75

Change-Id: I03bed44bafdebbcd22f487e59ef0de45dfbf3463