Gallery2: Fix cropped picture cannot be saved.

When click the saveButton to save the cropped picture,
We found the source picture uri and the cropped picture
uri are the same,which cause the cropped picture can
not be saved.

Closed file Stream of mInStream before re-open it
for the same file.

CRs-Fixed: 622666

Change-Id: Ifcaa39ea76c141021259fad891411c59f7587903