Add a method enable encryption.

This is for testing and needs to be cleaned up.

Change-Id: I71cd5412f7096dc13d9ab61229ee9846c6f0006a
diff --git a/include/storage/IMountService.h b/include/storage/IMountService.h
index 68ccd95..472d8e5 100644
--- a/include/storage/IMountService.h
+++ b/include/storage/IMountService.h
@@ -67,6 +67,7 @@
     virtual bool isObbMounted(const String16& filename) = 0;
     virtual bool getMountedObbPath(const String16& filename, String16& path) = 0;
     virtual int32_t decryptStorage(const String16& password) = 0;
+    virtual int32_t encryptStorage(const String16& password) = 0;
 };
 
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