[Compute] vm host group create: make --platform-fault-domain-count required and update help (#15751)

src/azure-cli/azure/cli/command_modules/vm/_params.py

@@ -498,7 +498,7 @@ def load_arguments(self, _):
 
     with self.argument_context('vm host group create') as c:
         c.argument('platform_fault_domain_count', options_list=["--platform-fault-domain-count", "-c"], type=int,
-                   help="Number of fault domains that the host group can span. Allowed values: 1, 2, 3")
+                   help="Number of fault domains that the host group can span.")
         c.argument('zones', zone_type)
 
     for scope in ["vm host", "vm host group"]:

src/azure-cli/azure/cli/command_modules/vm/custom.py

@@ -3365,7 +3365,7 @@ def list_proximity_placement_groups(client, resource_group_name=None):
 
 
 # region dedicated host
-def create_dedicated_host_group(cmd, client, host_group_name, resource_group_name, platform_fault_domain_count=None,
+def create_dedicated_host_group(cmd, client, host_group_name, resource_group_name, platform_fault_domain_count,
                                 automatic_placement=None, location=None, zones=None, tags=None):
     DedicatedHostGroup = cmd.get_models('DedicatedHostGroup')
     location = location or _get_resource_group_location(cmd.cli_ctx, resource_group_name)