Add TEST_MAPPING for system/security/fsverity

Since the fsverity build manifest is used in CompOS, run its test in
presubmit here.

Bug: N/A
Test: TH
Change-Id: If8f86774635dc7e143035b5b4b49f88c01f22ca7
diff --git a/fsverity/TEST_MAPPING b/fsverity/TEST_MAPPING
new file mode 100644
index 0000000..b327cb8
--- /dev/null
+++ b/fsverity/TEST_MAPPING
@@ -0,0 +1,7 @@
+{
+  "presubmit": [
+    {
+      "name": "ComposHostTestCases"
+    }
+  ]
+}