SnapdragonCamera: Change default burst count for CS to 4

Change the default burst count for Clearsight to 4 frames each.
This allows us to better guarantee to have 3 valid pairs.
Also use 1 less than burst count for actual Clearsight process.

CRs-Fixed: 993611, 1019859
Change-Id: I16a5fd1bc31092b5a91c70e637c7559b86b69b3d
1 file changed