Disable Gmail during notification test

Bug: 30442298
Change-Id: Ia9c03ca8301da0946347599048eabb21a47a560f
diff --git a/tests/jank/UbSystemUiJankTests/src/android/platform/systemui/tests/jank/SystemUiJankTests.java b/tests/jank/UbSystemUiJankTests/src/android/platform/systemui/tests/jank/SystemUiJankTests.java
index b5ebda2..173623e 100644
--- a/tests/jank/UbSystemUiJankTests/src/android/platform/systemui/tests/jank/SystemUiJankTests.java
+++ b/tests/jank/UbSystemUiJankTests/src/android/platform/systemui/tests/jank/SystemUiJankTests.java
@@ -24,22 +24,21 @@
 import android.content.pm.PackageManager;
 import android.graphics.Rect;
 import android.os.Bundle;
+import android.os.Environment;
 import android.os.RemoteException;
 import android.os.SystemClock;
 import android.support.test.jank.GfxMonitor;
 import android.support.test.jank.JankTest;
 import android.support.test.jank.JankTestBase;
+import android.support.test.timeresulthelper.TimeResultLogger;
 import android.support.test.uiautomator.By;
 import android.support.test.uiautomator.BySelector;
 import android.support.test.uiautomator.UiDevice;
 import android.support.test.uiautomator.UiObject;
 import android.support.test.uiautomator.UiObject2;
-import android.support.test.uiautomator.UiObjectNotFoundException;
 import android.support.test.uiautomator.UiSelector;
 import android.support.test.uiautomator.Until;
-import android.support.test.timeresulthelper.TimeResultLogger;
 import android.util.Log;
-import android.os.Environment;
 import android.widget.Button;
 
 import java.io.File;
@@ -76,6 +75,9 @@
             .getAbsolutePath(), "autotester.log");
     private static final File RESULTS_FILE = new File(Environment.getExternalStorageDirectory()
             .getAbsolutePath(), "results.log");
+    private static final String GMAIL_PACKAGE_NAME = "com.google.android.gm";
+    private static final String DISABLE_COMMAND = "pm disable-user ";
+    private static final String ENABLE_COMMAND = "pm enable ";
 
     private UiDevice mDevice;
     private List<String> mLaunchedPackages = new ArrayList<>();
@@ -158,6 +160,7 @@
     }
 
     public void prepareNotifications() throws Exception {
+        blockNotifications();
         goHome();
         mDevice.openNotification();
         SystemClock.sleep(100);
@@ -186,7 +189,16 @@
                 getClass().getSimpleName(), getName()), TIMESTAMP_FILE);
     }
 
-    public void cancelNotifications(Bundle metrics) throws IOException {
+    public void blockNotifications() throws Exception {
+        mDevice.executeShellCommand(DISABLE_COMMAND + GMAIL_PACKAGE_NAME);
+    }
+
+    public void unblockNotifications() throws Exception {
+        mDevice.executeShellCommand(ENABLE_COMMAND + GMAIL_PACKAGE_NAME);
+    }
+
+    public void cancelNotifications(Bundle metrics) throws Exception {
+        unblockNotifications();
         TimeResultLogger.writeTimeStampLogEnd(String.format("%s-%s",
                 getClass().getSimpleName(), getName()), TIMESTAMP_FILE);
         NotificationManager nm = (NotificationManager) getInstrumentation().getTargetContext()