Bug 1550422 - P7. Add VR process selector to prefs module. r=spohl

Will be needed to remove gfxPrefs in favor of StaticPrefs

Differential Revision: https://phabricator.services.mozilla.com/D31015

--HG--
extra : moz-landing-system : lando

modules/libpref/components.conf

@@ -18,7 +18,7 @@ Classes = [
         'type': 'mozilla::Preferences',
         'headers': ['mozilla/Preferences.h'],
         'constructor': 'mozilla::Preferences::GetInstanceForService',
-        'processes': ProcessSelector.ALLOW_IN_GPU_RDD_AND_SOCKET_PROCESS,
+        'processes': ProcessSelector.ALLOW_IN_GPU_RDD_VR_AND_SOCKET_PROCESS,
     },
     {
         'cid': '{064d9cee-1dd2-11b2-83e3-d25ab0193c26}',