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/paths_test.go b/android/paths_test.go
index 46e3e1f..ec5e598 100644
--- a/android/paths_test.go
+++ b/android/paths_test.go
@@ -21,6 +21,7 @@
 	"strings"
 	"testing"
 
+	"github.com/google/blueprint/pathtools"
 	"github.com/google/blueprint/proptools"
 )
 
@@ -206,6 +207,10 @@
 	inRoot         bool
 }
 
+func (moduleInstallPathContextImpl) Fs() pathtools.FileSystem {
+	return pathtools.MockFs(nil)
+}
+
 func (m moduleInstallPathContextImpl) Config() Config {
 	return m.baseModuleContext.config
 }