SurfacePackage: Add release method

Oversight, the SurfacePackage holds a reference to the SurfaceControl
which is protected by a close-guard. We need a way to close it
explicitly. Going to follow up with a patch to have SurfaceView
manage the lifetime when the SurfacePackage is consumed, but want
to make sure this explicit release gets in ASAP.

Bug: 149591513
Test: Existing tests pass
Change-Id: I7276a2440c38cc6d859b79b4c3ee57bc122ce2a6

api/current.txt

@@ -53616,6 +53616,7 @@ package android.view {
 
   public static final class SurfaceControlViewHost.SurfacePackage implements android.os.Parcelable {
     method public int describeContents();
+    method public void release();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
     field @NonNull public static final android.os.Parcelable.Creator<android.view.SurfaceControlViewHost.SurfacePackage> CREATOR;
   }

core/java/android/view/SurfaceControlViewHost.java

@@ -52,7 +52,7 @@ public class SurfaceControlViewHost {
      * a SurfaceView by calling {@link SurfaceView#setChildSurfacePackage}.
      */
     public static final class SurfacePackage implements Parcelable {
-        private final SurfaceControl mSurfaceControl;
+        private SurfaceControl mSurfaceControl;
         private final IAccessibilityEmbeddedConnection mAccessibilityEmbeddedConnection;
 
         SurfacePackage(SurfaceControl sc, IAccessibilityEmbeddedConnection connection) {
@@ -97,6 +97,16 @@ public class SurfaceControlViewHost {
             out.writeStrongBinder(mAccessibilityEmbeddedConnection.asBinder());
         }
 
+        /**
+         * Release the SurfaceControl associated with the SurfacePackage.
+         */
+        public void release() {
+            if (mSurfaceControl != null) {
+                mSurfaceControl.release();
+             }
+             mSurfaceControl = null;
+        }
+
         public static final @NonNull Creator<SurfacePackage> CREATOR
              = new Creator<SurfacePackage>() {
                      public SurfacePackage createFromParcel(Parcel in) {