Migrate sdk package to a per test build directory

Bug: 182885307
Test: m nothing
Change-Id: I051f2572ce5e94e2a3a66cf7663797178b7d1506
diff --git a/sdk/testing.go b/sdk/testing.go
index a5519f8..6df402c 100644
--- a/sdk/testing.go
+++ b/sdk/testing.go
@@ -16,8 +16,6 @@
 
 import (
 	"fmt"
-	"io/ioutil"
-	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -30,7 +28,7 @@
 )
 
 var sdkFixtureFactory = android.NewFixtureFactory(
-	&buildDir,
+	nil,
 	apex.PrepareForTestWithApexBuildComponents,
 	cc.PrepareForTestWithCcDefaultModules,
 	genrule.PrepareForTestWithGenRuleBuildComponents,
@@ -326,28 +324,3 @@
 	// The final output zip.
 	outputZip string
 }
-
-var buildDir string
-
-func setUp() {
-	var err error
-	buildDir, err = ioutil.TempDir("", "soong_sdk_test")
-	if err != nil {
-		panic(err)
-	}
-}
-
-func tearDown() {
-	_ = os.RemoveAll(buildDir)
-}
-
-func runTestWithBuildDir(m *testing.M) {
-	run := func() int {
-		setUp()
-		defer tearDown()
-
-		return m.Run()
-	}
-
-	os.Exit(run())
-}