audioflinger: fix wait for media.log service

commit e2cf8295 disabled media.log service but did not skip binding
to this service when audioflinger starts which caused a systematic
timeout and a 5 second delay in audioflinger start sequence.

Bug: 165702394
Bug: 169105682
Test: SuccessiveBootTest
Change-Id: I892c2120f290ef52b34d320b281ab8faf2b5b0ea