Make sure server start up before test.

When run this testcase, client get service before
the server didn't start up. it cause noSuchElementException.
So add sleep make sure server start up.

Bug: 194873308
test: run vts -m hidl_test_java

Change-Id: Iec2b5cebf7fbd889615cf76456ab3c7a84cb0365
(cherry picked from commit 55f2deb8953c8282bf012e8bfe32f49afd944944)
Merged-In: Iec2b5cebf7fbd889615cf76456ab3c7a84cb0365
diff --git a/test/java_test/hidl_test_java.py b/test/java_test/hidl_test_java.py
index 2a5d8b3..ccafd88 100644
--- a/test/java_test/hidl_test_java.py
+++ b/test/java_test/hidl_test_java.py
@@ -18,6 +18,7 @@
 import os
 import subprocess
 import unittest
+import time
 
 def run_cmd(cmd, ignore_error=False):
     print("Running command:", cmd)
@@ -42,6 +43,7 @@
             cleanup(client)
             cleanup(server)
             run_cmd("adb shell \"( %s %s -s ) </dev/null >/dev/null 2>&1 &\"" % (env, server))
+            time.sleep(2)
             run_cmd("adb shell %s %s -c" % (env, client))
         finally:
             cleanup(client)