Cut the dependency to libnativeloader

This library does not use libnativeloader, but depends on it just to use
headers of the library, which declares some functions of libdl.

Cut the dependency to the library by declaring the functions in place.

Bug: 71349776
Test: m -j libgraphicsenv

Change-Id: I3728d5e964c167b62173a0cb555fe3fbbbe5fc92