Add SysUI tests to androidx.compose drops

Test added for all androidx:

- SystemUIGoogleScreenshotTests

Tests added for specifically compose:

- SystemUIComposeCoreTests
- SystemUIComposeFeaturesTests
- SystemUIComposeGalleryTests

Copied set up from:

- frameworks/base/packages/SystemUI/compose/core/TEST_MAPPING
- frameworks/base/packages/SystemUI/TEST_MAPPING

Bug: b/257292433
Change-Id: Ie9ebc5f83e044324719adcb7146fe7cf52a4b4df
Merged-In: Ie9ebc5f83e044324719adcb7146fe7cf52a4b4df
Test: presubmit runs
2 files changed