Add support for CMakefile generation

Test: Manually generated CMakeLists.txt for gui/ui/aapt2.

Change-Id: I7dedc300c1e50b8e39bc58091b650c0bbe2c62da
diff --git a/Android.bp b/Android.bp
index 5e00a52..90566a4 100644
--- a/Android.bp
+++ b/Android.bp
@@ -129,6 +129,7 @@
         "cc/tidy.go",
         "cc/util.go",
 
+        "cc/cmakelists.go",
         "cc/compiler.go",
         "cc/installer.go",
         "cc/linker.go",