Convert the pose buffer into a more generic named buffer

* It's likely that we'll have more than one pose buffer
* It's cleaner to separate the vsync info into a separate buffer

Bug: 37001881
Bug: 37240552
Test: Added and manually ran TestNamedBuffersSetup
Change-Id: I76621d3cfa8c21c9d5d1e6e648854067673be9ab
22 files changed