p2p: finetune group join scan process

Sometimes scan might be occupied by WiFi, we just need to fire the scan
later but not abort the whole connecting.

No need to check scan res handler since we can also use previous scan
results with updated request.

Bug: 125390567
Test: manually test with FileGo
Change-Id: I31a99dfa6c9860d95f25a2b3c8ab8d91e64ffbde
1 file changed