feat(ui): Show inventory details if they exist

!8 closes #2

app/itam/forms/device/operating_system.py

@@ -1,6 +1,8 @@
 from django import forms
 from django.db.models import Q
 
+from app import settings
+
 from itam.models.device import DeviceOperatingSystem
 
 
@@ -16,3 +18,13 @@ class Update(forms.ModelForm):
             'operating_system_version',
         ]
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self.fields['_created'] = forms.DateTimeField(
+            label="Install Date",
+            input_formats=settings.DATETIME_FORMAT,
+            initial=kwargs['instance'].installdate,
+            disabled=True
+        )
+