Annotate backup CTS w/ @AppModeFull

Since B&R doesn't support instant apps.

Bug: 79485021
Test: atest CtsBackupTestCases
Test: atest CtsBackupHostTestCases
Change-Id: If636197f9214cded225832585cfe6c5d3c4e5d66
diff --git a/hostsidetests/backup/AllowBackup/src/AllowBackupTest.java b/hostsidetests/backup/AllowBackup/src/AllowBackupTest.java
index 643b594..efe52ae 100644
--- a/hostsidetests/backup/AllowBackup/src/AllowBackupTest.java
+++ b/hostsidetests/backup/AllowBackup/src/AllowBackupTest.java
@@ -21,6 +21,7 @@
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import android.platform.test.annotations.AppModeFull;
 import android.content.Context;
 import android.support.test.runner.AndroidJUnit4;
 import android.util.Log;
@@ -41,6 +42,7 @@
  *
  */
 @RunWith(AndroidJUnit4.class)
+@AppModeFull
 public class AllowBackupTest {
     public static final String TAG = "AllowBackupCTSApp";
     private static final int FILE_SIZE_BYTES = 1024 * 1024;