SnapdragonCamera: Fix can't launch gallery after switch storage

Camera can't query media URI successfully when we switch storage path.
Because camera use a static final field to hold storage path name which
is only initialized once and will not change any more, even if camera
use a static method to initialize this field.

By replacing this static final field with a static method can avoid
this issue, as static method will get real time value.

Change-Id: I49c2d81afe0e872483b4ab353c94746165c5a294
1 file changed