[Sana bug] bug fix for 2K model config (#10340)
* fix the Positinoal Embedding bug in 2K model;
* Change the default model to the BF16 one for more stable training and output
* make style
* substract buffer size
* add compute_module_persistent_sizes
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Co-authored-by: yiyixuxu <yixu310@gmail.com>
