Implement CopyFileFromLocal of MTPDeviceAsyncDelegate.
CopyFileFromLocal is a method to copy a local file to the device. This method will be used in CopyInForeingFile of AsyncFileUtil.
A CL to connect CopyFileFromLocal to CopyInForeingFile will come later when all other write operations (e.g. delete) are implemented.
BUG=413541
TEST=none; manually tested with changing write_supported variable in volume_manager.cc to true.
Review URL: https://codereview.chromium.org/
947943002
Cr-Commit-Position: refs/heads/master@{#319205}