Revert "Delete code used to read content:// URIs from MediaPlayerService"

This reverts commit fa2219509c820a0a274542b9c8a35257da627208.

Reason for revert: Moves failure on bad URIs from setDataSource to prepare, b/279586249

Change-Id: I6f04e387027f229e4e9a4c0a09e9acae9935f6bf
diff --git a/media/libmediaplayerservice/ActivityManager.h b/media/libmediaplayerservice/ActivityManager.h
new file mode 100644
index 0000000..451a004
--- /dev/null
+++ b/media/libmediaplayerservice/ActivityManager.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ActivityManager_H
+#define ActivityManager_H
+
+#include <utils/String16.h>
+
+namespace android {
+
+// Perform a ContentProvider.openFile() call for the given URI.
+//
+// Returns the native file descriptor for the opened stream, < 0 on error.
+extern int openContentProviderFile(const String16& uri);
+
+}
+
+#endif