Fix portable build on build server by removing depenency on ANDROID_HOST_OUT

Change-Id: I713a156468d14e07c784013c3c37a18c3c075a71
diff --git a/src/common_test.h b/src/common_test.h
index 0167424..62e7561 100644
--- a/src/common_test.h
+++ b/src/common_test.h
@@ -446,6 +446,15 @@
     return StringPrintf("%s/framework/%s.jar", GetAndroidRoot(), jar_prefix.c_str());
   }
 
+  std::string GetTestAndroidRoot() {
+    if (IsHost()) {
+      const char* host_dir = getenv("ANDROID_HOST_OUT");
+      CHECK(host_dir != NULL);
+      return host_dir;
+    }
+    return GetAndroidRoot();
+  }
+
   const DexFile* OpenTestDexFile(const char* name) {
     CHECK(name != NULL);
     std::string filename;