Soong generates libraries.txt files for vndk

These files were generated by Make. This is an effort to converting make
to soong.

These files are created under a known location: $SOONG_OUT_DIR/vndk
- llndk.libraries.txt
- vndksp.libraries.txt
- vndkcore.libraries.txt
- vndkprivate.libraries.txt
- vndkcorevariant.libraries.txt
- vndk.libraries.txt: merged all of above with tags

The last one is used by 'check-vndk-list'.
(See the topic)

Others will be packaged by VNDK APEX of current VNDK.
(This is not merged yet. After landing, a follow-up CL will be
followed.)

Bug: 141019581
Bug: 141450808
Test: m check-vndk-list
Change-Id: I9a24f6975bd4b226a94f61a13d43857dcdce6b88