- change GraphicsAllocatoin::AllocationType to scoped enumeration
so that ALLOCATION_TYPE_ prefix in every enum value can be removed
- all accesses are typed (example AllocationType::IMAGE)
- Rename allocationType to AllocationUsage to eliminate confusion
with multiple AllocationType enums / types
Change-Id: I16003297ecfcb0aaa5779ad00706c5d983914bbe