Don't rewrite LLNDK dependencies with .llndk suffix

Rewriting LLNDK dependencies with .llndk suffix requries referencing
a global data structure to determine if a given library is an LLNDK
library and therefore needs the .llndk suffix.  References to
global data structures from mutators must be removed to support
incremental Soong analysis.  Instead, move the LLNDK stubs rules
into the vendor variant of the implementing cc_library so that
the original name can be used.

As an incremental step, the llndk_library modules are left in
place, and the properties are copied into the cc_library via
the dependency specified by the llndk_stub property.  A followup
will move the LLNDK properties directly into the cc_library and
delete the llndk_library modules.

The global list of LLNDK libraries is kept for now as it is used
to generate the vndk.libraries.txt file.

Bug: 170784825
Test: m checkbuild
Test: compare Soong outputs
Test: all Soong tests
Change-Id: I2a942b21c162541a49e27b2e5833c9aebccff1d0