Create a smoke test for api_bp2build workspace

This test builds an "empty" filegroup. Running it can be useful to
verify that the api_bp2build workspace has been setup correctly.

Test: TH
Change-Id: I78639a2dcdeb659b2d6fdf6abc85d85c4fb697bf
diff --git a/tests/bp2build_bazel_test.sh b/tests/bp2build_bazel_test.sh
index 8c2ce48..6477dac 100755
--- a/tests/bp2build_bazel_test.sh
+++ b/tests/bp2build_bazel_test.sh
@@ -231,4 +231,11 @@
   fi
 }
 
+# Smoke test to verify api_bp2build worksapce does not contain any errors
+function test_api_bp2build_empty_build() {
+  setup
+  run_soong api_bp2build
+  run_bazel build --config=android --config=api_bp2build //:empty
+}
+
 scan_and_run_tests