bp2build: block src == name for prebuilt_* modules

src == name causes circular dependency errors, instead mark these as
unconverted and don't create modules for them.

Test: m bp2build and verify boringssl_self_test.zygote64.rc unconverted
Change-Id: I5d5fdd7e14830cd685816064cd0377998d07293c
diff --git a/bp2build/prebuilt_etc_conversion_test.go b/bp2build/prebuilt_etc_conversion_test.go
index 5b2d609..e237303 100644
--- a/bp2build/prebuilt_etc_conversion_test.go
+++ b/bp2build/prebuilt_etc_conversion_test.go
@@ -346,3 +346,17 @@
 		ExpectedErr: fmt.Errorf("label attribute could not be collapsed"),
 	})
 }
+
+func TestPrebuiltEtcNoConversionIfSrcEqualsName(t *testing.T) {
+	runPrebuiltEtcTestCase(t, Bp2buildTestCase{
+		Description: "",
+		Filesystem:  map[string]string{},
+		Blueprint: `
+prebuilt_etc {
+    name: "foo",
+    filename: "fooFilename",
+		src: "foo",
+}`,
+		ExpectedBazelTargets: []string{},
+	})
+}