Add "block drafts" feature

Design doc:
https://docs.google.com/document/d/16AX1tKa1CGSWwZtbW42h1uHy8SEPuv1ZjT_oHxc0UUI/edit

Fixed: twpowertools:84
Change-Id: Ibb172113774c5e2cab14e3d87a178bafed85df0b
diff --git a/templates/manifest.gjson b/templates/manifest.gjson
index 2faf7fb..800f2ae 100644
--- a/templates/manifest.gjson
+++ b/templates/manifest.gjson
@@ -52,6 +52,9 @@
 #if defined(CHROMIUM || GECKO)
     "https://support.google.com/*",
 #endif
+#if defined(CHROMIUM || CHROMIUM_MV3)
+    "declarativeNetRequestWithHostAccess",
+#endif
     "storage",
     "alarms"
   ],
@@ -85,6 +88,15 @@
     }
 #endif
   ],
+#if defined(CHROMIUM || CHROMIUM_MV3)
+  "declarative_net_request": {
+    "rule_resources": [{
+      "id": "blockDrafts",
+      "enabled": false,
+      "path": "rulesets/blockDrafts.json"
+    }]
+  },
+#endif
 #if defined(CHROMIUM || GECKO)
   "browser_action": {},
 #endif