Revert "wanghao:according to sd card to distinguish copy path"

This reverts commit 82baa09698b7323ad3859fdebe09801f3b606a35.
wanghao:when copying data from assets, depending on whether there sd card to specify the copy path
Merge pull request #254 from lwanghaol/ios-style

wanghao:when copying data from assets, depending on whether there sd card to specify the copy path