Partially Revert "Check VINTF compatibility at OTA generation time."

This partially reverts commit 9276cf02.

Reason for revert: broke mixed build

Put META/{system,vendor}_{manifest,matrix}.xml back because mixed builds
needs this.

Bug: 140217956
Test: mainline builds

Change-Id: I80898a17d6b86b17114b729d905dd9ab10bc927a