gsid: Make createPartition() don't preempttively clear installer_ am: c4d64008ac am: 124afd8926

Original change: https://android-review.googlesource.com/c/platform/system/gsid/+/1585026

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I4bcd3d82a5d7680f201dcbbb411e86b12d2b026a