Give clear distinction between active source/active routing path

Previously in HdmiControlSerivce, active routing path was mixed with
the physical address of the active source, but these two concepts needs
clearer distinction.

Defined a new variable for active source that contains both logical/physical
address to keep active routing path separate. This change makes it possible
to write the flow more closely to the guideline.

Also added to this CL is flag notifyInputChange, which allows the device/
routing change triggered by external event to trigger InputChangeListener
to get TIF notified. For routing control, the device info passed to TIF
has the path information in the field mPhysicalAddress (other fields are
invalid).

Bug: 16519939
Change-Id: I8b400bc48e874b0866500655773aea38ab945fe4