Add ios_chrome_reading_list_egtests as a try job.

Add ios_chrome_reading_list_egtests to gn_isolate_map.pyl and
ios-simulator-eg.json.

BUG=706922

Review-Url: https://codereview.chromium.org/2790683003
Cr-Commit-Position: refs/heads/master@{#461125}
diff --git a/testing/buildbot/gn_isolate_map.pyl b/testing/buildbot/gn_isolate_map.pyl
index 6ddffa818..4ad06da 100644
--- a/testing/buildbot/gn_isolate_map.pyl
+++ b/testing/buildbot/gn_isolate_map.pyl
@@ -536,6 +536,11 @@
     "type": "raw",
     "args": [],
   },
+  "ios_chrome_reading_list_egtests": {
+    "label": "//ios/chrome/test/earl_grey:ios_chrome_reading_list_egtests",
+    "type": "raw",
+    "args": [],
+  },
   "ios_chrome_settings_egtests": {
     "label": "//ios/chrome/test/earl_grey:ios_chrome_settings_egtests",
     "type": "raw",