lvm wrapper: Set SourceFormat as per number of channels

Bug: 171585865
Test: poc in bug

Change-Id: I9bcf11110c0da052b6a142289570da40a6f409d1
Merged-In: I9bcf11110c0da052b6a142289570da40a6f409d1
(cherry picked from commit e820941572fb3796126f54d01535dc640bfa3636)
1 file changed