Revert "Sandbox soong_build by changing to root directory"

This reverts commit 05c25ccb4adb5329add700b533416c226cdbfa96.

Reason for revert: broke absolute OUT_DIR
Bug: 146437378

Change-Id: I523ed79d40e1c1ef040212ba794a7a084abea75d
diff --git a/android/androidmk.go b/android/androidmk.go
index dbf3aa8..f3c15e4 100644
--- a/android/androidmk.go
+++ b/android/androidmk.go
@@ -323,7 +323,7 @@
 		return
 	}
 
-	err := translateAndroidMk(ctx, absolutePath(transMk.String()), androidMkModulesList)
+	err := translateAndroidMk(ctx, transMk.String(), androidMkModulesList)
 	if err != nil {
 		ctx.Errorf(err.Error())
 	}
@@ -364,8 +364,8 @@
 	}
 
 	// Don't write to the file if it hasn't changed
-	if _, err := os.Stat(absolutePath(mkFile)); !os.IsNotExist(err) {
-		if data, err := ioutil.ReadFile(absolutePath(mkFile)); err == nil {
+	if _, err := os.Stat(mkFile); !os.IsNotExist(err) {
+		if data, err := ioutil.ReadFile(mkFile); err == nil {
 			matches := buf.Len() == len(data)
 
 			if matches {
@@ -383,7 +383,7 @@
 		}
 	}
 
-	return ioutil.WriteFile(absolutePath(mkFile), buf.Bytes(), 0666)
+	return ioutil.WriteFile(mkFile, buf.Bytes(), 0666)
 }
 
 func translateAndroidMkModule(ctx SingletonContext, w io.Writer, mod blueprint.Module) error {