Introduce ComposeScreenshotTestRule for Compose UIs

This CL introduces the ComposeScreenshotTestRule to easily create a
screenshot diff test of a given Composable for multiple configurations
(devices, theme and orientation).

An actual Compose diff test will be added in a follow-up CL to keep the
size of this one reasonable.

Test: atest ExampleFeatureScreenshotTests
Bug: 230832101
Change-Id: I597dd621eb927354f3a8512da3e0331dd40acb98