Export apex_available_baseline to soong_injection

So that it can be used in the bazel implementation.

Bug: 268006095
Test: m nothing, check that it's in out/soong/soong_injection
Change-Id: I1520dd874076dee7fa083648d0790b060d658e5a
diff --git a/bp2build/conversion_test.go b/bp2build/conversion_test.go
index 8c24093..8c1d2ae 100644
--- a/bp2build/conversion_test.go
+++ b/bp2build/conversion_test.go
@@ -84,8 +84,10 @@
 
 func TestCreateBazelFiles_Bp2Build_CreatesDefaultFiles(t *testing.T) {
 	testConfig := android.TestConfig("", make(map[string]string), "", make(map[string][]byte))
-	files := soongInjectionFiles(testConfig, CreateCodegenMetrics())
-
+	files, err := soongInjectionFiles(testConfig, CreateCodegenMetrics())
+	if err != nil {
+		t.Error(err)
+	}
 	expectedFilePaths := []bazelFilepath{
 		{
 			dir:      "android",