AOSP/Messaging - Added LOCAL_COMPATIBILITY_SUITE := device-tests to fix...

AOSP/Messaging - Added LOCAL_COMPATIBILITY_SUITE := device-tests to fix "Missing test_suite setting for test".

+ Added keepclass ContactPickerFragment to fix the following exception.
  Caused by: java.lang.ClassNotFoundException: Didn't find class "com.android.messaging.ui.contact.ContactPickerFragment"

Bug: 126516784

Test: make messagingtests and tested the messaging UI manually. Ran the following CTS tests on Pixel phone.

$ make -j 40
  -rw-r--r-- 1 rtenneti primarygroup 8624061 Feb 27 10:55 out/target/product/marlin/system/app/messaging/messaging.apk

$ make messagingtests -j
  -rw-r--r-- 1 rtenneti primarygroup 729713 Feb 27 10:33 out/target/product/marlin/testcases/messagingtests/messagingtests.apk

$ adb install -r -d out/target/product/marlin/system/app/messaging/messaging.apk

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

$ adb shell am instrument -w com.android.messaging.test
  Time: 13.18
  OK (113 tests)

CTS tests for Mesaging app
---------------------------
$ ./development/testrunner/runtest.py --path cts/tests/app/src/android/app/cts/NotificationTest.java
  android.app.cts.NotificationTest:...........................
  Time: 0.263
  OK (27 tests)

atest
-----
$ cd .../packages/apps/Messaging
$ atest
  messagingtests: Passed: 113, Failed: 0, Ignored: 0
  All tests passed!

Change-Id: I559b25aeb536489478fb3511b611e76da1891874