CEC: Do not send <ARC Terminated> when init request gets rejected

System audio may reject <Request ARC Initiation> with a response
<Feature Abort> or just time out. Do not send <Request ARC Terminated>
in response so as not to turn off the ARC mode, as it may not be
the intended behavior.

Bug: 19928094

Change-Id: I469dfa53bf35dfbca7daa86a69763b10551663ec