alarm_test already runs in presubmit am: 670b0afded

Original change: https://android-review.googlesource.com/c/platform/external/grpc-grpc/+/1653127

Change-Id: I86dbb3626c24398d4753b2744318a7009a3bad53
diff --git a/TEST_MAPPING b/TEST_MAPPING
deleted file mode 100644
index 9b5629f..0000000
--- a/TEST_MAPPING
+++ /dev/null
@@ -1,8 +0,0 @@
-{
-  "postsubmit" : [
-    {
-      "name" : "alarm_test",
-      "host" : true
-    }
-  ]
-}