Package Manager does not display any result on using "Canvas" keyword for Unity UI Package.

Steps to repro:
1. Create a new project.
2. Windows > Package Manager.
3. In the Search field Enter "Canvas" keyword.

Actual result:
No result found for Canvas.

Expected result:
Unity UI Package is displayed in the search result.

Package Version :
1.0.0

Tested in Unity Version:
2019.3.0a3. 2019.2.0b1.

Environment:
Windows & Mac.