Start nfs service for micro ltp test

[coolgw]

nfs-server service is disabled by default in micro lead nfs related case such as statx07 failed.

• Related ticket: https://progress.opensuse.org/issues/161918
• Needles: na
• Verification run: installation job: https://openqa.suse.de/tests/14810586# case job: https://openqa.suse.de/tests/14810610#step/statx07/7 https://openqa.suse.de/tests/14837330#step/statx07/7

NOTE: No vsftpd found in current sle-micro. so make another workaround in code.

localhost:~ # zypper lr -u
Repository priorities are without effect. All enabled repositories share the same priority.

# | Alias                                                   | Name     | Enabled | GPG Check | Refresh | URI
--+---------------------------------------------------------+----------+---------+-----------+---------+--------------------------------------------------------------------------------
1 | SUSE_Linux_Micro_6.1_x86_64:SL-Micro-6.1-Debuginfo-Pool | SL-Mic-> | No      | ----      | ----    | http://openqa.suse.de/assets/repo/SL-Micro-Packages-6.1-x86_64-Debug-Build3.1/
2 | SUSE_Linux_Micro_6.1_x86_64:SL-Micro-6.1-Pool           | SL-Mic-> | Yes     | (r ) Yes  | No      | http://openqa.suse.de/assets/repo/SL-Micro-Packages-6.1-x86_64-Build3.1/
3 | SUSE_Linux_Micro_6.1_x86_64:SL-Micro-6.1-Source-Pool    | SL-Mic-> | No      | ----      | ----    | http://openqa.suse.de/assets/repo/SL-Micro-Packages-6.1-x86_64-Source-Build3.1/
4 | qa-head                                                 | qa-head  | Yes     | (  ) No   | Yes     | http://download.suse.de/ibs/QA:/Head/ALP-Standard-Core-1.0-Build/
localhost:~ # zypper se ftp
Refreshing service 'SUSE_Linux_Micro_6.1_x86_64'.
Loading repository data...
Reading installed packages...

S | Name             | Summary                               | Type
--+------------------+---------------------------------------+-----------
  | qa_test_ftpload  | ftp download test                     | package
  | qa_test_ftpload  | ftp download test                     | srcpackage
i | system-user-tftp | System user and group tftp            | package
i | tftp             | Trivial File Transfer Protocol (TFTP) | package

    Note: For an extended search including not yet activated remote resources please use 'zypper
    search-packages'.