fix: encrypt adminUsername (#2804)

Author: CasLubbers

values-schema.yaml

@@ -1681,6 +1681,9 @@ properties:
           adminPassword:
             type: string
             x-secret: '{{ randAlphaNum 20 }}'
+          adminUsername:
+            type: string
+            x-secret: ''
           postgresqlPassword:
             type: string
             description: This password was generated and cannot be changed without manual intervention.
@@ -1876,6 +1879,7 @@ properties:
             x-secret: ''
           adminUsername:
             type: string
+            x-secret: ''
           theme:
             type: string
             default: otomi