OPP: Calculate file size if not provided.

Use case:
Send and receive vcard file through
OBEX multiple times (above 30 times)

Result:
Sometimes DUT is unable to begin the vcard sharing
A toast is showed saying "File unknown file could not be sent".

Root cause:
In Some race conditions InputStream.available() returns zero which
causing error.

Fix:
According to java documentation InputStream.available() method provides such a
weak guarantee, as it isn't guaranteed to return the total number of
bytes in the stream. This is fixed by reading the stream to
calculate the length.

Change-Id: I6d1b85a4f63fee9a2a6ce2e9c4bc77346114537c
CRs-Fixed: 1068783