Include RkpdAppStressTests in the rkpd MTS suite

Test: mts-tradefed run mts-rkpd
Change-Id: I425b1b2863b3d32a6783c51f81e39f5a57bbf21b
diff --git a/app/tests/stress/Android.bp b/app/tests/stress/Android.bp
index 8426c6f..e6b5704 100644
--- a/app/tests/stress/Android.bp
+++ b/app/tests/stress/Android.bp
@@ -31,6 +31,7 @@
     test_suites: [
         "general-tests",
         "device-tests",
+        "mts-rkpd",
     ],
     min_sdk_version: "UpsideDownCake",
     instrumentation_for: "rkpdapp",