Add recovery_available to prebuilt_etc.

The property is similar to the ones for cc_*, where it can additionally
create a recovery variant of the module when used.

Bug: 112780007
Test: Build mke2fs.conf with `recovery_available: true`.
Test: `go test -run TestPrebuiltEtc`
Change-Id: Ia04360d00453fa1f80022301feb369514f5e2b0b
diff --git a/android/prebuilt_etc_test.go b/android/prebuilt_etc_test.go
new file mode 100644
index 0000000..9244647
--- /dev/null
+++ b/android/prebuilt_etc_test.go
@@ -0,0 +1,93 @@
+// Copyright 2018 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package android
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+func testPrebuiltEtc(t *testing.T, bp string) *TestContext {
+	config, buildDir := setUp(t)
+	defer tearDown(buildDir)
+	ctx := NewTestArchContext()
+	ctx.RegisterModuleType("prebuilt_etc", ModuleFactoryAdaptor(PrebuiltEtcFactory))
+	ctx.PreDepsMutators(func(ctx RegisterMutatorsContext) {
+		ctx.BottomUp("prebuilt_etc", prebuiltEtcMutator).Parallel()
+	})
+	ctx.Register()
+	mockFiles := map[string][]byte{
+		"Android.bp": []byte(bp),
+		"foo.conf":   nil,
+		"bar.conf":   nil,
+		"baz.conf":   nil,
+	}
+	ctx.MockFileSystem(mockFiles)
+	_, errs := ctx.ParseFileList(".", []string{"Android.bp"})
+	FailIfErrored(t, errs)
+	_, errs = ctx.PrepareBuildActions(config)
+	FailIfErrored(t, errs)
+
+	return ctx
+}
+
+func setUp(t *testing.T) (config Config, buildDir string) {
+	buildDir, err := ioutil.TempDir("", "soong_prebuilt_etc_test")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	config = TestArchConfig(buildDir, nil)
+	return
+}
+
+func tearDown(buildDir string) {
+	os.RemoveAll(buildDir)
+}
+
+func TestPrebuiltEtcVariants(t *testing.T) {
+	ctx := testPrebuiltEtc(t, `
+		prebuilt_etc {
+			name: "foo.conf",
+			src: "foo.conf",
+		}
+		prebuilt_etc {
+			name: "bar.conf",
+			src: "bar.conf",
+			recovery_available: true,
+		}
+		prebuilt_etc {
+			name: "baz.conf",
+			src: "baz.conf",
+			recovery: true,
+		}
+	`)
+
+	foo_variants := ctx.ModuleVariantsForTests("foo.conf")
+	if len(foo_variants) != 1 {
+		t.Errorf("expected 1, got %#v", foo_variants)
+	}
+
+	bar_variants := ctx.ModuleVariantsForTests("bar.conf")
+	if len(bar_variants) != 2 {
+		t.Errorf("expected 2, got %#v", bar_variants)
+	}
+
+	baz_variants := ctx.ModuleVariantsForTests("baz.conf")
+	if len(baz_variants) != 1 {
+		t.Errorf("expected 1, got %#v", bar_variants)
+	}
+}