WSA/ViewRootImpl: Move resize detection to client

Part of the chain of moving surface size ownership to the client
and making relayout asynchronous. We were already sending Surface
size to the client so it's easy to just use that and avoid
sending an extra result flag.

Bug: 161937501
Test: Existing tests pass
Change-Id: I18a96616d2cf082197fbbd434a737ed77ba40e9c