OpenSSLCipher: multiple calls to updateAAD were ignored

Do to a missing assignment statement, only the first call to updateAAD
was honored and the rest were discarded.

(cherry picked from commit a23b05b327b9d8fefc44276c2fa80278ef210c0f)

Bug: 27371173
Change-Id: I1eb7dd7862fa3b1cf47194f83023c7ad1b2a466c
diff --git a/src/main/java/org/conscrypt/OpenSSLCipher.java b/src/main/java/org/conscrypt/OpenSSLCipher.java
index 47de94a..90f464e 100644
--- a/src/main/java/org/conscrypt/OpenSSLCipher.java
+++ b/src/main/java/org/conscrypt/OpenSSLCipher.java
@@ -1058,6 +1058,7 @@
                 byte[] newaad = new byte[newSize];
                 System.arraycopy(aad, 0, newaad, 0, aad.length);
                 System.arraycopy(input, inputOffset, newaad, aad.length, inputLen);
+                aad = newaad;
             }
         }