Bluetooth-OPP: Add android configchanges attribute in manifest

Android configchanges attribute is added to application manifest
so that activity will not close during orientation changes.

OPP cleanup api will be called in onDestroy instead of onPause.
Otherwise, if device went to suspend/display OFF during BTON activity
onPause is called and share file information is removed from hashmap
This will lead to transfer failure.

CRs-Fixed: 706665
Change-Id: I8c5f7a6e164e1efb1c14e964cce7910ead66e278