Add a TestApi to capture screenshots based on a specified display ID

Test: Run an existing test, PlatformScenarioTests:android.platform.test.scenario.sysui.lockscreen.PinBouncerFoldableUIScreenshotTest, that uses UiAutomation for screenshot.
Flag: EXEMPTED test api
Bug: 401504441
Change-Id: Icb7a25a9ba1058f13b8e4d4db5637b9524205715