[Package Manager] Text on Install and Remove button are not getting updated once operation is finished

Steps to Reproduce:

1. Create a new Project
2. Click on Window > Package Manager > 2D Sprite
3. Click on install button and wait till installation

Actual Result: The Button text is still "Install"

Expected Result: The Button text changes to Remove

Environment:
Mac 10.14 and Windows 10

Reproducible on:
2019.3.0a2, 2019.3.0a1

Working Fine on:
2019.2.0b2