Mark DeviceLoginScreenDefaultVirtualKeyboardEnabled as deprecated

This policy was superseded by DeviceLoginScreenVirtualKeyboardEnabled

BUG=chromium:1096164

Change-Id: I506c114e6cbd2a38d71a7c128eb90f916108376a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2485751
Commit-Queue: Chris Sharp <csharp@chromium.org>
Reviewed-by: Amr Aboelkher <amraboelkher@google.com>
Reviewed-by: Amr Aboelkher <amraboelkher@chromium.org>
Reviewed-by: Pavol Marko <pmarko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826949}

components/policy/resources/policy_templates.json

@@ -12548,11 +12548,14 @@
       'features': {
         'dynamic_refresh': True,
       },
+      'deprecated': True,
       'example_value': True,
       'id': 256,
       'caption': '''Set default state of the on-screen keyboard on the login screen''',
       'tags': [],
-      'desc': '''Setting the policy to True turns the on-screen keyboard on at sign-in. Setting the policy to False turns the on-screen keyboard off at sign-in.
+      'desc': '''This policy is deprecated, please use the <ph name="DEVICE_LOGIN_SCREEN_VIRTUAL_KEYBOARD_ENABLED_POLICY_NAME">DeviceLoginScreenVirtualKeyboardEnabled</ph> policy instead.
+
+      Setting the policy to True turns the on-screen keyboard on at sign-in. Setting the policy to False turns the on-screen keyboard off at sign-in.
 
       If you set the policy, users can temporarily turn the on-screen keyboard on or off. When the sign-in screen reloads or stays idle for a minute, it reverts to its original state.