Soong frontend for shared library fuzzing.

Additional context (for Googlers): go/android-fuzzing-shared

This patch adds the Soong frontend for shared library fuzzing. We
traverse dependencies at soong install time to find all transient shared
libraries that $module depends on. We then ask the Make backend to
depend on the shared library.

We also create the source:destination mappings between where the shared
libraries are built to where they should be installed to for fuzzing.
This is then depended on by the Make backend.

Bug: N/A
Test: m fuzz, note the contents of $ANDROID_PRODUCT_OUT/data/fuzz/lib,
and out/soong/fuzz-target-*.zip now has shared libraries.

Change-Id: Id7afbd34bc9c055110af96cd3c668b730d404aee