KV Prometheus kv_ep_mem_low_wat_percent_ratio value is incorrect

The kv_ep_mem_low_wat_percent_ratio and kv_ep_mem_high_wat_percent_ratio values exposed to Prometheus are converted to percentages incorrectly.

The values are generally supposed to be 0.75 and 0.85, but due to incorrect division by 100 end up being 0.0075 and 0.0085 respectively.

Note the values exposed to cbstats are correct. Since none of our Prometheus dashboards use the kv_ep_mem_high_wat_percent_ratio metrics (instead we use kv_ep_mem_low which is in bytes), we never noticed this issue.

This has been addressed by MB-61457.