[feature] Add way to specify start time for Bootstrapping Metrics

[rohit-kulk]

Using with Cruise Control version 2.4

When you go to UI - Monitor Tab and click - Bootstrap Metrics, it kicks off an API Call that gets stuck in an infinite loop (with no start and end times)

Cruise Control State -> Monitor State -> Bootstrap Metrics

curl GET kafkacruisecontrol/bootstrap?clearmetrics=true&start=0

Instead, bootstrap Metrics should have some option on UI for start and end-time
Ex. Start time = now - 1 day and End time = now

Not having this option on UI makes the UI unusable for Bootstrapping Metrics. I was able to fix this by running manual API Call and hard-code the start and end times.

curl GET  kafkacruisecontrol/bootstrap?clearmetrics=true&start=1591130000000&end=1591137027000