Add TEST_MAPPING for BetterTogether components

Bug: 224782289
Change-Id: I21ee4712a32d20e09779120d65aac882c7c08b2a
Test: Presubmit
diff --git a/media/TEST_MAPPING b/media/TEST_MAPPING
index 4385a80..803c33c 100644
--- a/media/TEST_MAPPING
+++ b/media/TEST_MAPPING
@@ -1,6 +1,9 @@
 {
   "presubmit": [
     {
+      "name": "CtsMediaBetterTogetherTestCases"
+    },
+    {
       "name": "CtsCameraTestCases",
       "options" : [
         {