Introduce a new TRAMP method `androidsu'

Introduce a new TRAMP method `androidsu'

* doc/misc/tramp.texi (Quick Start Guide): Document the new
method.

* etc/NEWS (Tramp): Announce new method.

* lisp/net/tramp-adb.el (tramp-adb-handle-file-attributes)
(tramp-adb-handle-directory-files-and-attributes)
(tramp-adb-handle-file-name-all-completions): Properly print
ls's exit status in the presence of a pipe.
(tramp-adb-handle-copy-file): If the androidsu backend is in
use, call cp rather than adb push.
(tramp-adb-send-command): Disable ADB-specific code under
androidsu.
(tramp-adb-send-command-and-check): New argument
COMMAND-AUGMENTED-P.

* lisp/net/tramp-androidsu.el (tramp, tramp-adb, tramp-sh)
(tramp-androidsu-method, add-to-list)
(tramp-androidsu-maybe-open-connection)
(tramp-androidsu-generate-wrapper)
(tramp-androidsu-handle-access-file)
(tramp-androidsu-handle-add-name-to-file)
(tramp-androidsu-handle-copy-directory)
(tramp-androidsu-adb-handle-copy-file)
(tramp-androidsu-adb-handle-delete-directory)
(tramp-androidsu-adb-handle-delete-file)
(tramp-androidsu-handle-directory-file-name)
(tramp-androidsu-handle-directory-files)
(tramp-androidsu-adb-handle-directory-files-and-attributes)
(tramp-androidsu-handle-dired-uncache)
(tramp-androidsu-adb-handle-exec-path)
(tramp-androidsu-handle-expand-file-name)
(tramp-androidsu-handle-file-accessible-directory-p)
(tramp-androidsu-adb-handle-file-attributes)
(tramp-androidsu-handle-file-directory-p)
(tramp-androidsu-handle-file-equal-p)
(tramp-androidsu-adb-handle-file-executable-p)
(tramp-androidsu-adb-handle-file-exists-p)
(tramp-androidsu-handle-file-group-gid)
(tramp-androidsu-handle-file-in-directory-p)
(tramp-androidsu-sh-handle-file-local-copy)
(tramp-androidsu-handle-file-locked-p)
(tramp-androidsu-handle-file-modes)
(tramp-androidsu-adb-handle-file-name-all-completions)
(tramp-androidsu-handle-file-name-as-directory)
(tramp-androidsu-handle-file-name-case-insensitive-p)
(tramp-androidsu-handle-file-name-completion)
(tramp-androidsu-handle-file-name-directory)
(tramp-androidsu-handle-file-name-nondirectory)
(tramp-androidsu-handle-file-newer-than-file-p)
(tramp-androidsu-handle-file-notify-add-watch)
(tramp-androidsu-handle-file-notify-rm-watch)
(tramp-androidsu-handle-file-notify-valid-p)
(tramp-androidsu-adb-handle-file-readable-p)
(tramp-androidsu-handle-file-regular-p)
(tramp-androidsu-handle-file-remote-p)
(tramp-androidsu-handle-file-selinux-context)
(tramp-androidsu-handle-file-symlink-p)
(tramp-androidsu-adb-handle-file-system-info)
(tramp-androidsu-handle-file-truename)
(tramp-androidsu-handle-file-user-uid)
(tramp-androidsu-adb-handle-file-writable-p)
(tramp-androidsu-handle-find-backup-file-name)
(tramp-androidsu-handle-insert-directory)
(tramp-androidsu-handle-insert-file-contents)
(tramp-androidsu-handle-list-system-processes)
(tramp-androidsu-handle-load, tramp-androidsu-handle-lock-file)
(tramp-androidsu-handle-make-auto-save-file-name)
(tramp-androidsu-adb-handle-make-directory)
(tramp-androidsu-handle-make-lock-file-name)
(tramp-androidsu-handle-make-nearby-temp-file)
(tramp-androidsu-adb-handle-make-process)
(tramp-androidsu-sh-handle-make-symbolic-link)
(tramp-androidsu-handle-memory-info)
(tramp-androidsu-handle-process-attributes)
(tramp-androidsu-adb-handle-process-file)
(tramp-androidsu-adb-handle-rename-file)
(tramp-androidsu-adb-handle-set-file-modes)
(tramp-androidsu-adb-handle-set-file-times)
(tramp-androidsu-handle-set-visited-file-modtime)
(tramp-androidsu-handle-shell-command)
(tramp-androidsu-handle-start-file-process)
(tramp-androidsu-handle-substitute-in-file-name)
(tramp-androidsu-handle-temporary-file-directory)
(tramp-androidsu-adb-handle-get-remote-gid)
(tramp-androidsu-adb-handle-get-remote-groups)
(tramp-androidsu-adb-handle-get-remote-uid)
(tramp-androidsu-handle-unlock-file)
(tramp-androidsu-handle-verify-visited-file-modtime)
(tramp-androidsu-handle-write-region)
(tramp-androidsu-file-name-handler-alist)
(tramp-androidsu-file-name-p, tramp-androidsu-file-name-handler)
(tramp-register-foreign-file-name-handler)
(tramp-adb-connection-local-default-ps-profile, shell)
(tramp-unload-hook, tramp-androidsu): New file.

(cherry picked from commit babe6a5e948985f961ffd36f64323950abd98b7f)