Improve Tuner VTS Configuration: Enable Descrambling

This CL allows vendors to configure the Descrambling data flow in their
configuration files for the Tuner Hardware. Their connections were
checked to ensure their validity. Additionally, vendors can now give an
extra list of optional filters that can be utilized in the data flow.

Bug: b/182519645

Test: vts-tradefed run vts --module VtsHalTvTunerTargetTest
Change-Id: Iaa216876307571afa3ae6baf4624d0da14657439