assemble_vintf: don't warn too much.

This partially reverts commit 441fd2d532f0e26cdcb41aaacacfe45286eb98f1.

Reason for revert: reland the change without making hard errors.

Bug: 136042734
Bug: 116614862
Change-Id: I4dc6e10d7e15ff1e3565448c54bf05cb2931b07e
1 file changed