Rename soong generated super to super_image

To align with the naming conventions of other soong generated partition
image modules.

Test: m out/soong/.intermediates/build/soong/fsgen/aosp_cf_x86_64_phone_generated_super_image/android_common/aosp_cf_x86_64_phone_generated_super_image.img --soong-only
Change-Id: Ib2182cbd3b60a18330c39abab94939835bbe1246