Support --build-dir commandline flag for {run,install}_mandoline.py

mandoline/tools/android/run_mandoline.py

Index: mandoline/tools/android/run_mandoline.py
diff --git a/mandoline/tools/android/run_mandoline.py b/mandoline/tools/android/run_mandoline.py
index c06e008b52f174d4d1c32af9ad09dd33bdbb43f4..cf9139d1fda0f9d91220ebacd0af96cb3805775a 100755
--- a/mandoline/tools/android/run_mandoline.py
+++ b/mandoline/tools/android/run_mandoline.py
@@ -55,6 +55,7 @@ def main():
                            default=True, action='store_true')
   debug_group.add_argument('--release', help='Release build', default=False,
                            dest='debug', action='store_false')
+  parser.add_argument('--build-dir', help='Build directory')
   parser.add_argument('--target-cpu', help='CPU architecture to run for.',
                       choices=['x64', 'x86', 'arm'], default='arm')
   parser.add_argument('--device', help='Serial number of the target device.')
@@ -62,7 +63,8 @@ def main():
                       default=False, action='store_true')
   runner_args, args = parser.parse_known_args()
 
-  config = Config(target_os=Config.OS_ANDROID,
+  config = Config(build_dir=runner_args.build_dir,
+                  target_os=Config.OS_ANDROID,
                   target_cpu=runner_args.target_cpu,
                   is_debug=runner_args.debug,
                   apk_name='Mandoline.apk')