Finish Tramp's implementation of 'nofollow

Finish Tramp's implementation of 'nofollow

* lisp/net/tramp-adb.el (tramp-adb-handle-file-local-copy):
Do not use 'nofollow.
(tramp-adb-handle-set-file-modes):
* lisp/net/tramp-smb.el (tramp-smb-handle-set-file-modes):
* lisp/net/tramp-sudoedit.el (tramp-sudoedit-handle-set-file-modes):
* lisp/net/tramp-sh.el (tramp-sh-handle-set-file-modes):
Handle FLAG properly.
(tramp-get-remote-chmod-h): Adapt implementation.

* test/lisp/net/tramp-tests.el (tramp-get-remote-chmod-h): Declare.
(tramp--test-ignore-make-symbolic-link-error): Revert last change.
(tramp-test20-file-modes): Adapt test.