Change extra_size from hardcoded 1 to CONF.volume.volume_size_extend

test_volume_from_snapshot has extra_size hardcoded to 1 and it expects
the returned size increased by 1GB. This does not work with PowerFlex
cinder driver because PowerFlex/VxFlex OS requires volumes to be sized
in multiples of 8GB. Even if 1GB is given, 8GB will be actually used
when powerflex_round_volume_capacity = True.

Closes-Bug: #1949927
Change-Id: I04c3d6145fbc201355d38a7a058a37791227f733
1 file changed