Focus on time picker when entering value with keyboard

### Problem Statement

When I use the Sentry time picker and enter a value on the keyboard to set a custom period (eg. 2h for 2 hours, 3d for 3 days, 1w for last week, etc) I **always** try to lock it in by hitting enter. This does nothing until I hit the arrow key to select the first (often only) entry, and then hit Enter. Just a bit of friction that gets a bit annoying.


### Solution Brainstorm

Focusing on the first entry so that enter works immediately would be great.

### Product Area

Other