AOSP/ContactsTests - update the Contacts test package version to target P (28) or higher.

Bug: 115499280

Test: manual - Ran the following tests on Pixel phone. Tested the Contacts UI.

$ make -j 40
  -rw-r--r-- 1 rtenneti primarygroup 10195809 Feb  4 12:57 out/target/product/marlin/system/product/priv-app/Contacts/Contacts.apk
r
$ make ContactsTests -j
  -rw-r--r-- 1 rtenneti primarygroup 1601132 Feb  4 13:00 out/target/product/marlin/testcases/ContactsTests/ContactsTests.apk

$ adb install -r out/target/product/marlin/system/product/priv-app/Contacts/Contacts.apk

$ adb install -r out/target/product/marlin/testcases/ContactsTests/ContactsTests.apk

$ adb shell am instrument -w com.android.contacts.tests/android.support.test.runner.AndroidJUnitRunner
  + No change in tests behavior before and after the change.

Change-Id: I42bfd8405ec25c8df2bacb355bd93767cb5208ff
diff --git a/tests/AndroidManifest.xml b/tests/AndroidManifest.xml
index e3d9820..47dd928 100644
--- a/tests/AndroidManifest.xml
+++ b/tests/AndroidManifest.xml
@@ -17,7 +17,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.android.contacts.tests">
 
-    <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="25" />
+    <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="28" />
 
     <uses-permission android:name="android.permission.READ_CONTACTS" />
     <uses-permission android:name="android.permission.WRITE_CONTACTS" />