NNAPI VTS fix from NNAPI CL: Cleanup HalInterfaces.h

Prior to this CL, HalInterfaces.h polluted the global namespace through
the "using" declarations. To fix b/72880287, those names were put in a
new ::android::nn::hal namespace. This CL fixes the compilation errors
that occur due to this cleanup.

Bug: 72880287
Test: mma
Change-Id: Idb228e37615af7c0343a09f9a51de378e63bdb5a