[jnigen] Rethrow exception in gradle stub (https://github.com/dart-lang/jnigen/issues/237)

pkgs/jnigen/lib/src/tools/android_sdk_tools.dart

diff --git a/pkgs/jnigen/lib/src/tools/android_sdk_tools.dart b/pkgs/jnigen/lib/src/tools/android_sdk_tools.dart
index a3f53a3..466863c 100644
--- a/pkgs/jnigen/lib/src/tools/android_sdk_tools.dart
+++ b/pkgs/jnigen/lib/src/tools/android_sdk_tools.dart
@@ -91,6 +91,7 @@
     } catch (Exception e) {
       System.err.println("$_gradleCannotFindJars")
       System.err.println("$_leftOverStubWarning")
+      throw e
     }
   }
 }