AOSP/Messaging - update the Messaging version to target P (28) or higher. Fixed tests in messagingtests. All tests pass/work.

+ ParticipantRefreshTest - Added UIIntents and FakeDataModel. Fixed the errors in the data verification.
+ GetOrCreateConversationActionTest - conversation already exists (changed the assert).
+ ConversationFragmentTest - Return mockDraftMessageData even if createDraftMessageData is called with null argument.
  These tests weren't passing witout any changes (they weren't even starting without the target version update).

Bug: 119503204
Bug: 115499280

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

$ make -j 40

$ make messagingtests -j

$ ls -l out/target/product/marlin/system/app/messaging/messaging.apk
-rw-r--r-- 1 rtenneti primarygroup 8716364 Nov 30 15:43 out/target/product/marlin/system/app/messaging/messaging.apk

$ ls -l  out/target/product/marlin/testcases/messagingtests/messagingtests.apk
-rw-r--r-- 1 rtenneti primarygroup 627313 Nov 30 15:45 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
   Test results for InstrumentationTestRunner=.........................................
   Time: 12.921

   OK (113 tests)

   The following is from logcat output:

   11-30 23:47:31.861  6569  6590 I TestRunner: passed: testBindingReference(com.android.messaging.datamodel.BindingTest)
   11-30 23:47:31.868  6569  6590 I TestRunner: passed: testBindingStartsUnbound(com.android.messaging.datamodel.BindingTest)
   ...
   11-30 23:47:44.705  6569  6590 I TestRunner: passed: testGServiceGet(com.android.messaging.util.BugleGservicesTest)

Change-Id: I8f67da024d86f15f7430b803237ae4cff4d8e2c2

AndroidManifest.xml

@@ -18,7 +18,7 @@
     package="com.android.messaging"
     android:installLocation="internalOnly">
 
-    <uses-sdk android:minSdkVersion="19" android:targetSdkVersion="24" />
+    <uses-sdk android:minSdkVersion="19" android:targetSdkVersion="28" />
 
     <!-- Application holds CPU wakelock while working in background -->
     <uses-permission android:name="android.permission.WAKE_LOCK" />