Reset mIsActiveSource in source local device when new Active Source is

recorded

In Hdmi local source device, mIsActiveSource is used to represent if the
current device is the current Active Source or not. But when we receive
<System Audio Mode Request> or <Active Source> with a new Active Source,
we did not update mIsActiveSource when reset Active Source.

Test: manual
Bug: 131629012
Change-Id: Ief369a724fe9c2bac13db7af24cdbbfb5b732185
(cherry picked from commit cf0c95a51776f7a3b54f50d61709abcb362c324c)