[Feature/Improvement] Status bar background color match workout screen color

[a-mabe]

Purpose: As a user, I would like the status bar to match the workout screen.

More details: Some more details on the feature/improvement

Currently, the status bar is a different color than the rest of the screen during the workout. See screenshot:

The status bar color should match the current color of the workout screen, i.e. green, red, or black depending on the timer interval.

Acceptance Criteria:

• Status bar color matches the rest of the workout screen for a cohesive appearance.

[a-mabe]

Closed in #106