Get stream list again if it doesn't seem to have done it before

Get stream list again if it doesn't seem to have done it before

stream list is obtained from PulseAudio via DBus during the initialization
of the focus server. Normally, PulseAudio is launched before this focus
server. It has no problem with the normal situation. If the sequence is
reversed for some reason, these new codes can get a chance to make it right.

[Version] 0.12.43
[Issue Type] Fault tolerance

Change-Id: I95007aa7ea8aecbf9f7212c6b0d2daaf6bee7806
Signed-off-by: Sangchul Lee <sc11.lee@samsung.com>