Handle non IPv6 packet in getRaPios

Bug: 338061061

Test: atest ThreadNetworkIntegrationTests:android.net.thread.BorderRoutingTest

Change-Id: Ia637dc8ec4cca919bd1957148ec2c104ab1895ac
diff --git a/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt b/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt
index 07d0390..316f570 100644
--- a/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt
+++ b/thread/tests/integration/src/android/net/thread/utils/IntegrationTestUtils.kt
@@ -388,7 +388,12 @@
         raMsg ?: return pioList
 
         val buf = ByteBuffer.wrap(raMsg)
-        val ipv6Header = Struct.parse(Ipv6Header::class.java, buf)
+        val ipv6Header = try {
+            Struct.parse(Ipv6Header::class.java, buf)
+        } catch (e: IllegalArgumentException) {
+            // the packet is not IPv6
+            return pioList
+        }
         if (ipv6Header.nextHeader != OsConstants.IPPROTO_ICMPV6.toByte()) {
             return pioList
         }