Enable sendKeyEvent() for all types of devices

Previously there was only sendKeyEvent() implementation for TV and the
method was no-op for other devices. This change moves the event handling
logic into HdmiCecLocalDevice so as to make this method work on the
playback device.

Bug: 33285033
Test: Sent key event from playback device, and it worked.
Change-Id: I937502ab87ce823630b0f9a933355d5a4cc5e96a