istio-interop-testing: increase deadline to 5 sec to avoid deadline issue on aarch64 (#9497)

diff --git a/istio-interop-testing/src/test/java/io/grpc/testing/istio/EchoTestServerTest.java b/istio-interop-testing/src/test/java/io/grpc/testing/istio/EchoTestServerTest.java
index bc882d1..091a300 100644
--- a/istio-interop-testing/src/test/java/io/grpc/testing/istio/EchoTestServerTest.java
+++ b/istio-interop-testing/src/test/java/io/grpc/testing/istio/EchoTestServerTest.java
@@ -206,7 +206,7 @@
         ForwardEchoRequest.newBuilder()
             .setCount(COUNT_OF_REQUESTS_TO_FORWARD)
             .setQps(100)
-            .setTimeoutMicros(2000_000L) // 2000 millis
+            .setTimeoutMicros(5000_000L) // 5000 millis
             .setUrl("grpc://localhost:" + port2)
             .addHeaders(
                 Header.newBuilder().setKey("test-key1").setValue("test-value1").build())