Minor cleanup to DvrConfig processing in vrflinger

The intention of the previous code was to update the sequence number
so that the struct was only updated on new config changes. The
sequence number needs to be incremented to achieve that behavior.

This is minor, because the previous code is harmless: it just
sets the 16 byte struct every time through, which isn't much
different from the new code.

Bug: 66969271
Test: confirmed with VrCore change to set the DvrConfig struct.
Change-Id: Ica60e2dc8b7d852d56549bab574a6802cea592fc
(cherry picked from commit 4fa590c446e8103a6642e95e382ef8c7d9d1aa8e)