Fix generate-userimage-prop-dictionary getting called unnecessarily.

odm, odm_dlkm, vendor_dlkm call generate-userimage-prop-dictionary. This
appears to be inadvertent as it pulls in props from all the other
partitions. Instead, call generate-image-prop-dictionary which is
specific to one partition.

Bug: 198001223
Test: builds, treehugger green
Change-Id: Ib177c740068f1c087d517b363649551092038760