Revert "Add aggregate method"

None of the callers to the old aggregations mechanism were updated.

This reverts commit b1c75fa83af438facb070bc5138a262ae4436a10.

Bug: 64194
Change-Id: Iea1b638c19e936239e72f4bf6f0a18c4658af7c6
Merge "Revert "Add aggregate method""