audiopolicy: Handle legacy startOutput on output command thread too

* Fixes the build for legacy audio policy
* Broken by: de3b1c01146d2103f6bf56e2659a9c650734945a

Change-Id: I990ce609b3da81c462b35c7dd3f7b11d189e2d2e
Signed-off-by: Xuefer <xuefer@gmail.com>
1 file changed