Dockerfiles hardcoded one copy operation to x86; generalize to capture
ARM as well. Since the target directory cannot have any globs, we need
to manually check the right directory, then move the file.

Note that this is only necessary since we are forced to switch the
compiler, as Ubuntu's default gcc-11 does not work with FlexRIC. When
upgrading to Ubuntu 24, these lines should disappear and asan be
installed as normal. See commit 94497435 ("Upgrade CI images to
Ubuntu 22").