Mark the SelectableDates interface as Stable

Test: manual
Relnote: N/A
Bug: 271912022
Change-Id: Ia3a554beffc49cf216c5151265c7e39803f7307f
diff --git a/compose/material3/material3/api/public_plus_experimental_current.txt b/compose/material3/material3/api/public_plus_experimental_current.txt
index 659ab3e..7378d91 100644
--- a/compose/material3/material3/api/public_plus_experimental_current.txt
+++ b/compose/material3/material3/api/public_plus_experimental_current.txt
@@ -923,7 +923,7 @@
   @androidx.compose.material3.ExperimentalMaterial3Api @androidx.compose.runtime.Immutable public final class SelectableChipElevation {
   }
 
-  @androidx.compose.material3.ExperimentalMaterial3Api public interface SelectableDates {
+  @androidx.compose.material3.ExperimentalMaterial3Api @androidx.compose.runtime.Stable public interface SelectableDates {
     method public default boolean isSelectableDate(long utcTimeMillis);
     method public default boolean isSelectableYear(int year);
   }
diff --git a/compose/material3/material3/src/commonMain/kotlin/androidx/compose/material3/DatePicker.kt b/compose/material3/material3/src/commonMain/kotlin/androidx/compose/material3/DatePicker.kt
index 5f4d8f9..9e16c93 100644
--- a/compose/material3/material3/src/commonMain/kotlin/androidx/compose/material3/DatePicker.kt
+++ b/compose/material3/material3/src/commonMain/kotlin/androidx/compose/material3/DatePicker.kt
@@ -255,6 +255,7 @@
  * An interface that controls the selectable dates and years in the date pickers UI.
  */
 @ExperimentalMaterial3Api
+@Stable
 interface SelectableDates {
 
     /**