### What changes were proposed in this pull request?
`MRAppMasterWithCeleborn` disables `yarn.app.mapreduce.am.job.recovery.enable` and sets `mapreduce.job.reduce.slowstart.completedmaps` to 1 by default.
### Why are the changes needed?
MapReduce does not set the flag which indicates whether to keep containers across application attempts in ApplicationSubmissionContext. Meanwhile, make sure reduces are scheduled only after all map are completed. Therefore, `MRAppMasterWithCeleborn` could disable `yarn.app.mapreduce.am.job.recovery.enable` and set `mapreduce.job.reduce.slowstart.completedmaps` to 1 by default.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
`WordCountTest`
Closes#2525 from SteNicholas/CELEBORN-1434.
Authored-by: SteNicholas <programgeek@163.com>
Signed-off-by: mingji <fengmingxiao.fmx@alibaba-inc.com>
cd5609971f