Reapply "ANDROID: kheader: kheaders: Follow symlinks to source files"

This reverts commit 54568b8f.

Reapply after merge upstream changes to kbuild. Note there is now a make
${TAR} variable, so in theory we could remove this patch and instead use
the new environment variable as such:

  $ make TAR="tar --dereference"

Bug: 276339429
Cc: Yifan Hong <elsk@google.com>
Change-Id: Ic4edc024e8ca18bbd7b71ff5475c91d47cdc1e1f
Signed-off-by: Carlos Llamas <cmllamas@google.com>