Upgrade jsoncpp to 1.9.4

Bug: 170642246
Change-Id: Id1fae5a1b6421117f923c616718ee4b3571231e0
diff --git a/TEST_MAPPING b/TEST_MAPPING
new file mode 100644
index 0000000..3e990af
--- /dev/null
+++ b/TEST_MAPPING
@@ -0,0 +1,20 @@
+// Generated by update_crate_tests.py for tests that depend on this crate.
+{
+  "presubmit": [
+    {
+      "name": "keystore2_test"
+    },
+    {
+      "name": "libbinder_rs-internal_test"
+    },
+    {
+      "name": "rustBinderTestService"
+    },
+    {
+      "name": "rustBinderTest"
+    },
+    {
+      "name": "keystore2_km_compat_test"
+    }
+  ]
+}