Remote fetch device status (attributes and logs) command

This CL introduces a remote command that enables device administrators to remotely fetch device status (attributes and logs). Attributes were being uploaded every 3 hours and logs every 12 hours from the device side, and there was no way to trigger a remote refresh.

More context can be found by reading the design doc go/remote-audio-management

The new functionality was manually tested; remote reboot command was hijacked and rewired to decode into this command and then on the server side (CPanel admin) I clicked on "REBOOT NOW" and I observed the device attributes and logs being updated.

P.S. I've also fixed up some linter errors.

BUG=686389
TEST=Manually tested new behaviour.

Review-Url: https://codereview.chromium.org/2765463002
Cr-Original-Commit-Position: refs/heads/master@{#459037}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 35b9ec40290254e484cc17e76ee5205b618e23c9
diff --git a/device_management_backend.proto b/device_management_backend.proto
index 1bb7240..03f2646 100644
--- a/device_management_backend.proto
+++ b/device_management_backend.proto
@@ -1061,6 +1061,9 @@
 
     // Set device volume.
     DEVICE_SET_VOLUME = 2;
+
+    // Force a refresh of device status (attributes and logs).
+    DEVICE_FETCH_STATUS = 3;
   }
 
   // The command type.