Add SmartspaceView.setHorizontalPaddings.

This is needed so that Launcher can configure this horizontal padding
dynamically.

Flag: EXEMPT bugfix
Bug: 382345130
Test: N/A. Only add method to interface. Compiles and existing tests.
Change-Id: Id575904ea2f63a3ea199f2c170cca72b3e5cd42f
4 files changed