Fix CTS testLockTaskAfterReboot_tryOpeningSettings_deviceOwnerUser

1. testLockTaskAfterReboot_tryOpeningSettings_deviceOwnerUser starts
   android.settings.SETTINGS after ADB connection then it causes
   test failed.

2. This change makes CTS wait until kiosk mode working.

Test: run CTS testLockTaskAfterReboot_tryOpeningSettings_deviceOwnerUser
Bug: 127423609

Change-Id: I4ddc6d905b13ecb9d28188e6800990e557ad67e8
Signed-off-by: Sungmin Lee <insight.lee@lge.com>
diff --git a/hostsidetests/devicepolicy/src/com/android/cts/devicepolicy/DeviceOwnerTest.java b/hostsidetests/devicepolicy/src/com/android/cts/devicepolicy/DeviceOwnerTest.java
index 28dd552..49ff2b4 100755
--- a/hostsidetests/devicepolicy/src/com/android/cts/devicepolicy/DeviceOwnerTest.java
+++ b/hostsidetests/devicepolicy/src/com/android/cts/devicepolicy/DeviceOwnerTest.java
@@ -560,7 +560,7 @@
                     mPrimaryUserId);
 
             // Reboot while in kiosk mode and then unlock the device
-            getDevice().reboot();
+            rebootAndWaitUntilReady();
 
             // Try to open settings via adb
             executeShellCommand("am start -a android.settings.SETTINGS");