Revert "Revert "Normalize building generic system image with treble-common.mk""

We will selectively revert on a branch only.

This reverts commit 85c4945f46bccb7cb69fa39b280b11ffa6e04815.

Change-Id: I0eb869a0f2385fe66bd3cd0bc18a298ebe5b47da
4 files changed