Add a placeholder test to test IcmpPacketReader and sendPing

This will soon become an actual APF test.

Test: atest ApfIntegrationTest
Change-Id: I5c78b557177c96e3460a1057527f67de78290338
diff --git a/tests/cts/net/src/android/net/cts/ApfIntegrationTest.kt b/tests/cts/net/src/android/net/cts/ApfIntegrationTest.kt
index 8b66ed0..9cda156 100644
--- a/tests/cts/net/src/android/net/cts/ApfIntegrationTest.kt
+++ b/tests/cts/net/src/android/net/cts/ApfIntegrationTest.kt
@@ -336,4 +336,14 @@
             assertWithMessage("read/write $i byte prog failed").that(readResult).isEqualTo(program)
         }
     }
+
+    // TODO: this is a placeholder test to test the IcmpPacketReader functionality and will soon be
+    // replaced by a real test.
+    @Test
+    fun testPing() {
+        val data = ByteArray(56)
+        Random.nextBytes(data)
+        packetReader.sendPing(data)
+        assertThat(packetReader.expectPingReply()).isEqualTo(data)
+    }
 }