allow to create mar files for LibO with symbols

LibO with symbols mar files are around 1.5GB. I'm not yet sure if they
are really useful but at least we have the option to create them.
Most likely the better option is to use the crash reporter and upload
the symbol information there.

Change-Id: I7c5af9ca3b52f7d712e60115bf23da22240160bb

include/onlineupdate/mar_private.h

@@ -23,7 +23,7 @@
 
 /* Make sure the file is less than 500MB.  We do this to protect against
    invalid MAR files. */
-#define MAX_SIZE_OF_MAR_FILE ((int64_t)524288000)
+#define MAX_SIZE_OF_MAR_FILE ((int64_t)1824288000)
 
 /* Existing code makes assumptions that the file size is
    smaller than LONG_MAX. */