Auto-build/update codegen

Test: 1. Manually enter version/presence of build artifact,
and ensure `codegen FILENAME` still works
2. run codegen again without altering version, ensure no build triggered
Change-Id: I6f1dba0a476077c708bbea8ef558445107e5ad97
diff --git a/tests/Codegen/runTest.sh b/tests/Codegen/runTest.sh
index fe3adf9..bc1aae0 100755
--- a/tests/Codegen/runTest.sh
+++ b/tests/Codegen/runTest.sh
@@ -10,7 +10,7 @@
         return $?
     }
 
-    header_and_eval m -j16 codegen && \
+    header_and_eval m -j16 codegen_cli && \
         header_and_eval codegen $ANDROID_BUILD_TOP/frameworks/base/tests/Codegen/src/com/android/codegentest/SampleDataClass.java && \
         cd $ANDROID_BUILD_TOP &&
         header_and_eval mmma -j16 frameworks/base/tests/Codegen && \