Update shell open command to have a mode.

We need to open files for reading sometimes, so now
we can.

Test: manual

Change-Id: If089c1e7a4aac1d85784e070d2fccb04b9d84391
diff --git a/libs/binder/IShellCallback.cpp b/libs/binder/IShellCallback.cpp
index c793df3..23b83a6 100644
--- a/libs/binder/IShellCallback.cpp
+++ b/libs/binder/IShellCallback.cpp
@@ -39,11 +39,13 @@
     {
     }
 
-    virtual int openOutputFile(const String16& path, const String16& seLinuxContext) {
+    virtual int openFile(const String16& path, const String16& seLinuxContext,
+            const String16& mode) {
         Parcel data, reply;
         data.writeInterfaceToken(IShellCallback::getInterfaceDescriptor());
         data.writeString16(path);
         data.writeString16(seLinuxContext);
+        data.writeString16(mode);
         remote()->transact(OP_OPEN_OUTPUT_FILE, data, &reply, 0);
         reply.readExceptionCode();
         int fd = reply.readParcelFileDescriptor();
@@ -64,7 +66,8 @@
             CHECK_INTERFACE(IShellCallback, data, reply);
             String16 path(data.readString16());
             String16 seLinuxContext(data.readString16());
-            int fd = openOutputFile(path, seLinuxContext);
+            String16 mode(data.readString16());
+            int fd = openFile(path, seLinuxContext, mode);
             if (reply != NULL) {
                 reply->writeNoException();
                 if (fd >= 0) {