Add sphal and vndk namespaces to unrestricted

Add sphal and vndk namespaces to unrestricted

Binary executables compiled against libvulkan or libEGL/libGLES*
fundamentally depend on sphal libraries for their functionality. On
production builds, instead of building APKs, devs are always allowed to
use NDK toolchain to build binaries and push to /data/local/tmp to run.

Devs are doing such as to avoid issues with bundling resources,
extracting output, slower build times and flakier perf numbers. It's
also the preferred way for test factory which have cross-platform
devices, because they can automate the process using the same script if
using binary executables.

This change adds the sphal and vndk namespaces to unrestricted
configuration. This change also makes rs an optional namespace for sphal
namespace as it's only needed in system configuration. In addition, this
change has updated vndk namespace generation accordingly.

Bug: 156099573
Test: atest --test-mapping system/linkerconfig
Test: push a Vulkan binary to /data/local/tmp and run
Change-Id: Id09dbcf2ab33a599960f471cbc1b142b6d3eaa1a