Add verbose logs for vndk tag filtering

We've had multiple bugs about vndk tag filtering as the number of
android api versions increases. Add some easy verbose logs which can be
turned on for debugging if needed.

Bug: 337972017

Test: builds

Change-Id: I0bfe8b034da9f1e4bb1de956ff7f458cea0b470d
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>