Tor mentioned in Private Window when admin policy is enabled

[btlechowski]

Found when testing #454
Tor should not be mentioned because it is disabled by admin policy

Steps to Reproduce

Note: steps are copied from #454

1. Fresh install of Brave (clean profile)
2. Open regedit
3. For 64 bit, create the following keys:
   BraveSoftware\Brave
   under the existing key:
   HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Policies\
   (for 32 bit, you can edit HKEY_LOCAL_MACHINE\SOFTWARE\Policies\)
4. Create a DWORD value at this path called TorDisabled and set the value as 1
5. Launch Brave
6. Open Private Window

Actual result:

Tor is mentioned in Private Window

Note: Alt+Shift+n does not open Tor Window

Expected result:

Tor is not mentioned, because it is disabled via admin policy

Reproduces how often:

100% repro rate

Brave version (brave://version info)

Brave	1.3.101 Chromium: 79.0.3945.130 (Official Build) beta (64-bit)
Revision	e22de67c28798d98833a7137c0e22876237fc40a-refs/branch-heads/3945@{#1047}
OS	Windows 10 OS Version 1909

Brave	1.3.101 Chromium: 79.0.3945.130 (Official Build) beta (64-bit)
Revision	e22de67c28798d98833a7137c0e22876237fc40a-refs/branch-heads/3945@{#1047}
OS	Windows 7 Service Pack 1 (Build 7601.24544)

cc @brave/legacy_qa @bbondy @simonhong @rebron @bsclifton @tomlowenthal