MTP: Add support for dynamically adding and removing storage units

BUG: 3402847

Change-Id: I7da266061d949abcb6bb11c6faaa47b5e4a2a977
diff --git a/media/mtp/MtpStorage.h b/media/mtp/MtpStorage.h
index ace720b..858c9d3 100644
--- a/media/mtp/MtpStorage.h
+++ b/media/mtp/MtpStorage.h
@@ -17,6 +17,7 @@
 #ifndef _MTP_STORAGE_H
 #define _MTP_STORAGE_H
 
+#include "MtpTypes.h"
 #include "mtp.h"
 
 namespace android {
@@ -27,7 +28,7 @@
 
 private:
     MtpStorageID            mStorageID;
-    const char*             mFilePath;
+    MtpString               mFilePath;
     uint64_t                mMaxCapacity;
     // amount of free space to leave unallocated
     uint64_t                mReserveSpace;
@@ -44,7 +45,7 @@
     uint64_t                getMaxCapacity();
     uint64_t                getFreeSpace();
     const char*             getDescription() const;
-    inline const char*      getPath() const { return mFilePath; }
+    inline const char*      getPath() const { return (const char *)mFilePath; }
 };
 
 }; // namespace android