Plugin does not appear to be active especially when reload is disabled

To repro:

bazel run tensorboard/plugins/profile:profile_demo
bazel run tensorboard -- --logdir /tmp/profile_demo
# In browser, launch http://localhost:6006/#profile

Cause: due to a change in profile plugin (probably related to the dummy event file), there now is a race condition where when launching the app, plugins_listing says the plugin is not active. However, because we launched into the profile plugin, the profile plugin frontend makes the request and is able to resolve. Unfortunately, because our plugin system can control whether data reloads(1), tf-tensorboard never refetches(2) the plugins-listing causing the race condition to never correct.

(1): https://github.com/tensorflow/tensorboard/blob/90a386d1da4d9f477cb60b679f07aa98045d8c7e/tensorboard/plugins/profile/tf_profile_dashboard/tf-profile-dashboard.html#L687
(2): https://github.com/tensorflow/tensorboard/blob/90a386d1da4d9f477cb60b679f07aa98045d8c7e/tensorboard/components/tf_tensorboard/tf-tensorboard.html#L869-L882

Possible solution: Make certain core endpoint reload (environment and plugins_listing) in all situation.

EDIT:
This bug impacts the projector plugin too. When first loading the app, the projector plugin, although should be active, appears to be inactive. Only after another reload, it appears to be active. This is a regression from the previous version.

Reproduce the profile demo with the listed Bazel commands, then inspect tf_profile_dashboard/tf-profile-dashboard.html around line 687 and components/tf_tensorboard/tf-tensorboard.html around lines 869-882. Trace how reload-disabled plugins interact with the environment and plugins_listing requests. Done means profile and projector are shown as active on the initial load without requiring another reload.