gn2bp: fix output_dir arg for jni_generator.py

Test: m cronet_aml_base_base_jni_headers
Change-Id: I308763fa32b1fda312786f9de577159f2c21958d
diff --git a/tools/gn2bp/Android.bp.swp b/tools/gn2bp/Android.bp.swp
index cbfc048..739b2b1 100644
--- a/tools/gn2bp/Android.bp.swp
+++ b/tools/gn2bp/Android.bp.swp
@@ -269,7 +269,7 @@
          "--prev_output_dir " +
          "gen/base/android_runtime_jni_headers " +
          "--output_dir " +
-         "gen/jni_headers/base/android_runtime_jni_headers " +
+         "$(genDir)/jni_headers/base/android_runtime_jni_headers " +
          "--includes " +
          "../../../../../../base/android/jni_generator/jni_generator_helper.h " +
          "--jar_file " +
@@ -1020,7 +1020,7 @@
          "--prev_output_dir " +
          "gen/base/base_jni_headers " +
          "--output_dir " +
-         "gen/jni_headers/base/base_jni_headers " +
+         "$(genDir)/jni_headers/base/base_jni_headers " +
          "--includes " +
          "../../../../../../base/android/jni_generator/jni_generator_helper.h " +
          "--use_proxy_hash " +