[Bug]: Splash screen shows when running composable tests

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Is there a StackOverflow question about this issue?

- [X] I have searched StackOverflow

### What happened?

A bug happened!

When running UI Composable tests, the Splash Screen is displayed. To see this happen, run any test in NavigationUiTest.kt.

Screen shot for when running NavigationUiTest.compactWidth_compactHeight_showsNavigationBar() test:

Expected results:
Splash screen theme should not be shown when running compose UI tests. Instead, only the composable within composeTestRule.setContent should be displayed.

### Relevant logcat output

_No response_

### Code of Conduct

- [X] I agree to follow this project's Code of Conduct

Start with NavigationUiTest.kt and run a test such as NavigationUiTest.compactWidth_compactHeight_showsNavigationBar() to reproduce the splash screen. Inspect how composeTestRule.setContent is used and determine why the splash screen theme is shown during the UI test. Done means only the composable supplied to setContent is displayed.

Written by the indexing model from the issue text.