bluetooth: poll GetBluezSourceDevice

For some reason, if we repeat to call StartRecordingAudioSubprocess and
StopRecordingingAudioSubprocess too fast, sometimes the
StartRecordingAudioSubprocess will fail to list the bluez_source.
Poll for the GetBluezSourceDevice in StartRecordingAudioSubprocess to
make this function more stable.

BUG=b:191722792
TEST=test_that bluetooth_AdapterAUHealth. \
        au_hfp_wbs_dut_as_source_back2back_test

Change-Id: I727cbc664627410d1bc5a7541f08a981de310ae0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/chameleon/+/3467155
Reviewed-by: Shijin Abraham <shijinabraham@google.com>
Tested-by: John Lai <johnlai@google.com>
Reviewed-by: Shyh-In Hwang <josephsih@chromium.org>
Commit-Queue: John Lai <johnlai@google.com>
1 file changed