Added an event for default rule "Unprivileged Delegation of Page Faults Handling to a Userspace Process"

[GLVSKiriti]

What type of PR is this?

Uncomment one (or more) /kind <> lines:

/kind bug

/kind cleanup

/kind documentation

/kind tests

/kind feature

Any specific area of the project related to this PR?

Uncomment one (or more) /area <> lines:

/area commands

/area pkg

/area events

What this PR does / why we need it:
Added an event for default rule "Unprivileged Delegation of Page Faults Handling to a Userspace Process" as mentioned here

Which issue(s) this PR fixes:

Fixes #170

Special notes for your reviewer:

[GLVSKiriti]

This event is also tested against a running a falco instance and produces the critical priority log as expected on left terminal

[GLVSKiriti]

@FedeDP similarly this triggers irrespective of userfaultfd syscall is successful or not just an attempt is enough to trigger the rule so return nil;

event-generator/events/syscall/unprivileged_delegation_of_page_faults_handling_to_a_userspace_process.go

Lines 31 to 37 in d8b3ae6

	// To make user.uid != 0
	if err := becameUser(h, "daemon"); err != nil {
	return err
	}
	// Attempt to create userfaultfd syscall is enough
	unix.Syscall(unix.SYS_USERFAULTFD, 0, 0, 0)
	return nil

[poiana]

LGTM label has been added.

Git tree hash: ba7791d58984e180ddf7bc4b6a26b92443fbf5a4

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: GLVSKiriti, leogr

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [leogr]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment