Add support for RHSM customizations

Add support for RHSM customizations, which currently allow various
aspects of RHSM. Specifically enabling / disabling DNF plugins shipped
by subscription-manager package and setting a subset of options in the
rhsm.conf.

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

internal/cloudapi/v2/openapi.v2.yml

@@ -1036,6 +1036,47 @@ components:
       properties:
         import_keys:
           $ref: '#/components/schemas/ImportKeys'
+    DNFPluginConfig:
+      type: object
+      properties:
+        enabled:
+          type: boolean
+    SubManDNFPluginsConfig:
+      type: object
+      properties:
+        product_id:
+          $ref: '#/components/schemas/DNFPluginConfig'
+        subscription_manager:
+          $ref: '#/components/schemas/DNFPluginConfig'
+    SubManRHSMConfig:
+      type: object
+      properties:
+        manage_repos:
+          type: boolean
+    SubManRHSMCertdConfig:
+      type: object
+      properties:
+        auto_registration:
+          type: boolean
+    SubManConfig:
+      type: object
+      properties:
+        rhsm:
+          $ref: '#/components/schemas/SubManRHSMConfig'
+        rhsmcertd:
+          $ref: '#/components/schemas/SubManRHSMCertdConfig'
+    RHSMConfig:
+      type: object
+      properties:
+        dnf_plugins:
+          $ref: '#/components/schemas/SubManDNFPluginsConfig'
+        subscription_manager:
+          $ref: '#/components/schemas/SubManConfig'
+    RHSMCustomization:
+      type: object
+      properties:
+        config:
+          $ref: '#/components/schemas/RHSMConfig'
     UploadTarget:
       type: object
       required:
@@ -1368,6 +1409,8 @@ components:
           $ref: '#/components/schemas/Installer'
         rpm:
           $ref: '#/components/schemas/RPMCustomization'
+        rhsm:
+          $ref: '#/components/schemas/RHSMCustomization'
     SSHKey:
       type: object
       additionalProperties: false
@@ -1514,6 +1557,8 @@ components:
           $ref: '#/components/schemas/Installer'
         rpm:
           $ref: '#/components/schemas/RPMCustomization'
+        rhsm:
+          $ref: '#/components/schemas/RHSMCustomization'
     Container:
       type: object
       required: