Improve Tuner VTS: Generate Scan Combos

This CL allows the VTS to read a vendor's configuration file, determine
if the given devices could support the Scan dataflow, and runs the
integration tests with all valid frontends.

Bug: b/182519645

Test: vts-tradefed run vts --module VtsHalTvTunerTargetTest. Manual
tests with different input configuration files.

Change-Id: Ic6756e284090fbd1961a9ed12c1a4b541fb834b8