Messaging: Remove tests

Nobody runs them anyway

Change-Id: I2b07847509269af31430abc6cb0fb190f08d45f9

AndroidManifest.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!--
     Copyright (C) 2015 The Android Open Source Project
+    Copyright (C) 2024 The LineageOS Project
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
@@ -297,15 +298,6 @@
                 android:value="com.android.messaging.ui.conversation.ConversationActivity" />
         </activity>
 
-        <!-- Test activity that we use to host fragments/views. Unfortunately, apparently necessary
-             because Android framework test cases want activity to be in the instrumented package.
-             See http://developer.android.com/reference/android/test/ActivityInstrumentationTestCase2.html
-        -->
-        <activity
-            android:name=".ui.TestActivity"
-            android:configChanges="orientation|screenSize|keyboardHidden">
-        </activity>
-
         <activity
             android:name=".ui.debug.DebugMmsConfigActivity"
             android:configChanges="orientation|screenSize|keyboardHidden"