Bug 1854403 - Set privacy.partition.bloburl_per_double_partition_key pref to be true. r=timhuang

Differential Revision: https://phabricator.services.mozilla.com/D188840

modules/libpref/init/StaticPrefList.yaml

@@ -13184,7 +13184,7 @@
 
 - name: privacy.partition.bloburl_per_partition_key
   type: bool
-  value: @IS_NIGHTLY_BUILD@
+  value: true
   mirror: always
 
 - name: privacy.window.name.update.enabled