Restrict asan-smoke to KitKat and newer.

Change-Id: I4eec8450302e2d82d1f29c159baaf2e9f5464674
diff --git a/tests/device/asan-smoke/test_config.py b/tests/device/asan-smoke/test_config.py
index ec0df31..a4408a7 100644
--- a/tests/device/asan-smoke/test_config.py
+++ b/tests/device/asan-smoke/test_config.py
@@ -3,4 +3,6 @@
         return toolchain
     if not abi.startswith('armeabi'):
         return abi
+    if device_platform < 19:
+        return device_platform
     return None