* The extra STL libs are:
libc++abi.a [needed for ndk_libc++_static]
libandroid_support.a [always needed in NDK r16]
libunwind.a [needed for ARM32]
* The existing STL-dependency logic in linkShared only applies to shared
libraries. By moving it to STL deps, the extra STL libs are linked into
both shared libraries and executables.
* Remove the ndk_prebuilt_library/ndkPrebuiltLibraryFactory module type,
which is unused now.
* Reuse the ndk_prebuilt_static_stl module type to describe the extra
static libraries that are linked with both the static and shared libc++
STLs.
Bug: b/73133405
Test: manual
Change-Id: I3f73e4f882d39e6efa470073bb4fc8c42dff8253