Avoid searching non-existent dir

Don't call all-java-files-under src since there is no src directory

Change-Id: Id5d8b8ec4e0349c86edfbe1d0f58d50d9146cf43
diff --git a/Android.mk b/Android.mk
index a325a18..0ea691e 100644
--- a/Android.mk
+++ b/Android.mk
@@ -21,8 +21,6 @@
 
 LOCAL_MODULE_TAGS := optional
 
-LOCAL_SRC_FILES := $(call all-java-files-under, src)
-
 LOCAL_STATIC_JAVA_LIBRARIES := android-common com.android.emailcommon
 LOCAL_STATIC_JAVA_LIBRARIES += calendar-common