Tuner HAL VTS: Fix Memory Leak

This CL fixes an issue on the Tuner HAL VTS that lead to a memory leak.
Heap space was allocated to store Lnb Id's for dataflows without being
cleaned using Free(). The fix includes switching to the use of an
integer passed by reference. No heap memory is allocated.

Bug: b/240572001

Test: Test: ts-tradefed run vts --module VtsHalTvTunerTargetTest
Change-Id: I9fcad4c05f548ee4b64cfb34175f34834eec6c56