Rename UiSavedStateRegistry to SaveableStateRegistry

Relnote: UiSavedStateRegistry was renamed to SaveableStateRegistry, AmbientUiSavedStateRegistry was renamed to AmbientSaveableStateRegistry and both moved to androidx.compose.runtime.saveable package.
Test: ./gradlew bOs
Change-Id: I30224b3f671d01d6a2ae30a80405a69067e76838

diff --git a/compose/ui/ui/api/public_plus_experimental_current.txt b/compose/ui/ui/api/public_plus_experimental_current.txt
index 05ed0ae..ff52cbb 100644
--- a/compose/ui/ui/api/public_plus_experimental_current.txt
+++ b/compose/ui/ui/api/public_plus_experimental_current.txt

@@ -2183,7 +2183,7 @@
   public final class DebugUtilsKt {
   }
 
-  public final class DisposableUiSavedStateRegistryKt {
+  public final class DisposableSaveableStateRegistryKt {
   }
 
   public interface InspectableValue {