Do not link stub libraries from all namespaces

Do not link stub libraries from all namespaces

In current linkerconfig from all namespaces stub libraries are linked to
system namespace, which was required for APEX namespaces. However, as
linkerconfig checks dependencies from APEX namespaces now, this link is
excessive and can create unexpected interface from system. This change
removes redundant stub library link so namespaces can link to system
image with minimum set of libraries.

Bug: 156563692
Test: m -j passed && crosshatch_hwasasn booted
Change-Id: If43c954f376ede65bd2c3f682be6ae5d6866d3df