Revert g2: dexopt system to /cache

This reverts commit 207e25e4798ef52fd428916a18f7952b19857bf0

Change-Id: I2ad9830fe5f03e3b8cb7617c24f3779220cbc535
Revert g2: add optimization

This reverts commit 0f4ec9baedb576c980ae4804cb85dc4f5803234a

Change-Id: Ic65201117807a7cf0adb349f83b85e885b27cc37