Ensure we apply override configuration to the global one.

We are confusing clients by sending the correctly merged
override and global configurations through the primary
ActivityManager channel but then sending only
the global configuration through the window manager channels
ensure we always merge the configurations prior to sending
them to the client.

Bug: 26454664
Change-Id: I7183365e1c414f9a68564338c60e2f5283ddb57d