Add validation for hostpath in plex app

test/plex/1.7.7/questions.yaml

@@ -185,6 +185,8 @@ questions:
                       schema:
                         type: hostpath
                         required: true
+                        $ref:
+                          - "validations/hostPath"
         - variable: data
           label: "Data Volume"
           schema:
@@ -220,6 +222,8 @@ questions:
                       schema:
                         type: hostpath
                         required: true
+                        $ref:
+                          - "validations/hostPath"
         - variable: config
           label: "Config Volume"
           schema:
@@ -255,6 +259,8 @@ questions:
                       schema:
                         type: hostpath
                         required: true
+                        $ref:
+                          - "validations/hostPath"
         - variable: shared
           label: "Shared Volume"
           schema: