vmware_guest_disk/test: use less disk space

Reduce the amount of space that is used on the datastore during the
test. This allow use to use lighter storage environment during the test.

test/integration/targets/vmware_guest_disk/tasks/main.yml

@@ -48,7 +48,7 @@
           disk_mode: "independent_persistent"
           scsi_controller: 0
           scsi_type: 'paravirtual'
-          size_gb: 10
+          size_gb: 1
           state: present
           type: eagerzeroedthick
           unit_number: 2
@@ -56,7 +56,7 @@
           disk_mode: "independent_nonpersistent"
           scsi_controller: 0
           scsi_type: 'paravirtual'
-          size_gb: 10
+          size_gb: 1
           state: present
           type: eagerzeroedthick
           unit_number: 3
@@ -64,7 +64,7 @@
           disk_mode: "persistent"
           scsi_controller: 0
           scsi_type: 'paravirtual'
-          size_gb: 10
+          size_gb: 1
           state: present
           type: eagerzeroedthick
           unit_number: 4