Update minimum deviceQuota and description (Azure#16034)

Co-authored-by: Liran Chen <lirche@microsoft.com>

Author: 2 people

specification/iotsecurity/resource-manager/Microsoft.IoTSecurity/preview/2021-02-01-preview/defenderSettings.json

@@ -298,8 +298,8 @@
         "deviceQuota": {
           "type": "integer",
           "format": "int32",
-          "minimum": 1000,
-          "description": "Size of the device quota (as a opposed to a Pay as You Go billing model). Value is required to be in multiples of 1000."
+          "minimum": 0,
+          "description": "Size of the device quota. Value is required to be in multiples of 100."
         },
         "sentinelWorkspaceResourceIds": {
           "type": "array",