Updating API docs for dcmanager prestage command

Aligns the API doc with its current functionality.
Added missing prestage fields for_install and for_sw_deploy.

Story: 2010676
Task: 51556

Change-Id: I33825d015ede1919d8ba8d2d79da139ad4bca6b4
Signed-off-by: Cristian Mondo <cristian.mondo@windriver.com>

api-ref/source/api-ref-dcmanager-v1.rst

@@ -532,6 +532,8 @@ serviceUnavailable (503)
   - release: release
   - sysadmin_password: sysadmin_password
   - force: force
+  - for_install: for_install
+  - for_sw_deploy: for_sw_deploy
 
 Request Example
 ----------------

api-ref/source/parameters.yaml

@@ -302,6 +302,19 @@ extra_args:
   in: body
   required: false
   type: dictionary
+for_install:
+  description: |
+    Indicates whether the prestage should be for install.
+    This is the default if the parameter is not provided.
+  in: body
+  required: false
+  type: boolean
+for_sw_deploy:
+  description: |
+    Indicates whether the prestage should be for software deploy.
+  in: body
+  required: false
+  type: boolean
 force:
   description: |
     Indicates whether to disregard subcloud management alarm condition.

api-ref/source/samples/subclouds/subcloud-patch-prestage-request.json

@@ -1,5 +1,6 @@
 {
     "sysadmin_password": "XXXXXXX",
     "release": "21.12",
-    "force": "true"
+    "force": "true",
+    "for_install": "true"
 }