Don't crash just because invalid datasets were offered for restore

In practice, recognize that the current transport state may not yet
incorporate a valid restore data stream object, so don't go making
assumptions that it's usable / closeable / etc.

Bug 18379004

Change-Id: I221e04b5b83438e37455e025d67f412d3abb8c50

core/java/com/android/internal/backup/LocalTransport.java

@@ -35,6 +35,8 @@ import android.util.Log;
 
 import com.android.org.bouncycastle.util.encoders.Base64;
 
+import libcore.io.IoUtils;
+
 import java.io.BufferedOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
@@ -559,11 +561,7 @@ public class LocalTransport extends BackupTransport {
     // Full restore handling
 
     private void resetFullRestoreState() {
-        try {
-        mCurFullRestoreStream.close();
-        } catch (IOException e) {
-            Log.w(TAG, "Unable to close full restore input stream");
-        }
+        IoUtils.closeQuietly(mCurFullRestoreStream);
         mCurFullRestoreStream = null;
         mFullRestoreSocketStream = null;
         mFullRestoreBuffer = null;