[Android] Use os.exec in the test wrapper scripts.

build/android/gyp/create_test_runner_script.py

Index: build/android/gyp/create_test_runner_script.py
diff --git a/build/android/gyp/create_test_runner_script.py b/build/android/gyp/create_test_runner_script.py
index ca2287ff484743ac6e4b25f6c5ed7efdca62bf56..7734126e0fb3ad511301c354458f652cb1c5fbf2 100755
--- a/build/android/gyp/create_test_runner_script.py
+++ b/build/android/gyp/create_test_runner_script.py
@@ -19,7 +19,6 @@ SCRIPT_TEMPLATE = """\
 # This file was generated by build/android/gyp/create_test_runner_script.py
 
 import os
-import subprocess
 import sys
 
 def main():
@@ -36,8 +35,8 @@ def main():
   for arg, path in test_runner_path_args:
     test_runner_args.extend([arg, ResolvePath(path)])
 
-  test_runner_cmd = [test_runner_path] + test_runner_args + sys.argv[1:]
-  return subprocess.call(test_runner_cmd)
+  os.execv(test_runner_path,
+           [test_runner_path] + test_runner_args + sys.argv[1:])
 
 if __name__ == '__main__':
   sys.exit(main())