WM: Add PhoneWindowManagerLayoutTest

Test: runtest -x services/tests/servicestests/src/com/android/server/policy/PhoneWindowManagerLayoutTest.java
Change-Id: I85af4bdd023a274233362d42628de19483b0c4ea
diff --git a/services/tests/servicestests/Android.mk b/services/tests/servicestests/Android.mk
index a2ec234..e5ab44f 100644
--- a/services/tests/servicestests/Android.mk
+++ b/services/tests/servicestests/Android.mk
@@ -26,6 +26,7 @@
     platform-test-annotations \
     ShortcutManagerTestUtils \
     truth-prebuilt \
+    testables \
     testng
 
 LOCAL_AIDL_INCLUDES := $(LOCAL_PATH)/aidl