Rename NativeAllocationRegistry_Delegate in HostRuntime

This removes the _Delegate suffix in order to match with the real
NativeAllocationRegistry. That allows it to be used as is by layoutlib
and other clients.

Flag: NONE layoutlib for host
Bug: 322360037
Test: N/A
Change-Id: I0f5a209297ed1d2d78642fa56ca5102c1017369b