vndk-def: Add tag file support to deps-insight

This commit generalizes tag file support so that deps-insight won't
follow the dependencies to ineligible vndk-sp/vndk libs.

Bug: 37867089
Test: libandroid.so will not be tagged as vndk in the html output of
deps-insight tool.

Change-Id: I5482a45acf4232ae7fac1210043ca868b28211ff