feat: updates DevicePreviews.kt to use Devices constants

core/ui/src/main/kotlin/com/google/samples/apps/nowinandroid/core/ui/DevicePreviews.kt

@@ -17,13 +17,14 @@
 package com.google.samples.apps.nowinandroid.core.ui
 
 import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.tooling.preview.Devices
 
 /**
  * Multipreview annotation that represents various device sizes. Add this annotation to a composable
  * to render various devices.
  */
-@Preview(name = "phone", device = "spec:shape=Normal,width=360,height=640,unit=dp,dpi=480")
-@Preview(name = "landscape", device = "spec:shape=Normal,width=640,height=360,unit=dp,dpi=480")
-@Preview(name = "foldable", device = "spec:shape=Normal,width=673,height=841,unit=dp,dpi=480")
-@Preview(name = "tablet", device = "spec:shape=Normal,width=1280,height=800,unit=dp,dpi=480")
+@Preview(showBackground = true, name = "phone", device = Devices.PHONE)
+@Preview(showBackground = true, name = "desktop", device = Devices.DESKTOP)
+@Preview(showBackground = true, name = "foldable", device = Devices.FOLDABLE)
+@Preview(showBackground = true, name = "tablet", device = Devices.TABLET)
 annotation class DevicePreviews