[improve](routine load) adjust default values to make routine load more convenient to use (#42491)

[sollhui]

pick (#42491)

For a routine load job, it will be divided into many tasks, each of which is a transaction. Currently, the default time consumed(max_batch_interval) is 10 seconds. The benefits of increasing this value are:

1. Larger batch consumption can lead to better performance.
2. Reducing the number of transactions can alleviate the pressure of compaction and the conflicts of concurrent transaction submissions.

related doc: https://github.com/apache/doris-website/pull/1236/files

[doris-robot]

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1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
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[sollhui]

run buildall

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[doris-robot]

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