Explicitly chmod() for compatibility.

Apps typically have a umask() that prevents the mkdir() from setting
the requested permissions.

Bug: 27116987
Change-Id: Ia14e7e31531328ab36e902a864b3d2891feec544

core/java/android/app/ContextImpl.java

@@ -492,6 +492,7 @@ class ContextImpl extends Context {
         if (!file.exists()) {
             try {
                 Os.mkdir(file.getAbsolutePath(), 0771);
+                Os.chmod(file.getAbsolutePath(), 0771);
             } catch (ErrnoException e) {
                 if (e.errno == OsConstants.EEXIST) {
                     // We must have raced with someone; that's okay