Debian: Prevent automatic LV event activation

Historically, with CentOS, we had issues related to LV activation
occurring in a non-deterministic way and causing an assortment of
provisioning issues. More deterministic LV activation was achieved by
setting use_lvmetad = 0 in /etc/lvm/lvm.conf

In the migration to Debian, a much more recent version of the lvm2
package is in use. In one of the intervening versions of lvm2, lvmetad
was removed making use_lvmetad and the associated behavior now obsolete.

In some current random testing scenarios, emergency mode is seen when
booting the Debian ISO. Reviewing the systemd dump of services
initiating when emergency mode occurs, it is observed that LV activation
is occurring at a different time vs. a successful boot.

The Debian lvm2 version provides the configuration parameter
global/event_activation which when set to 0 will change LV activation
behavior so that when a PV appears pvscan is not called.

Test Plan:
PASS - Build ISO, install/provision in AIO-SX virtual/hardware labs
PASS - Perform numerous reboot cycles an observe no issues
PASS - Test on H/W setup that has shown emergency mode behavior to
       confirm that this version and associated config file change
       resolved emergency mode PV/LV activation issues

Test Plan:
PASS - Build ISO, install/provision in AIO-SX virtual/hardware labs

Signed-off-by: Robert Church <robert.church@windriver.com>
Depends-On: https://review.opendev.org/c/starlingx/integ/+/846453
Closes-Bug: #1979105
Change-Id: Ibae56a1da6135ea2f0a1fac76f1ce505a95588f5

lvm2-config/source-debian/lvm.conf

@@ -1052,7 +1052,7 @@ global {
 	# When event_activation is disabled, the system will generally run
 	# a direct activation command to activate LVs in complete VGs.
 	# This configuration option has an automatic default value.
-	# event_activation = 1
+	event_activation = 0
 
 	# Configuration option global/use_aio.
 	# Use async I/O when reading and writing devices.