{scripts/release} Disable git lfs cloning when generating API diff. (#6043)
{scripts/release} Disable git lfs cloning when generating API diff. (#6043)

The `scripts/release apidiff` command needs to create two local temporary clones of the repo in order to generate the API diff. Unfortunately, git lfs fails to clone local copies of a git repo, particularly when not using a `file://` prefix.

The fix is to disable git LFS cloning prior to the API diff temporary clone commands.

```bash
hint: The remote resolves to a file:// URL, which can only work with a
hint: standalone transfer agent.  See section "Using a Custom Transfer Type
hint: without the API server" in custom-transfers.md for details.

hint: The remote resolves to a file:// URL, which can only work with a
hint: standalone transfer agent.  See section "Using a Custom Transfer Type
hint: without the API server" in custom-transfers.md for details.

hint: The remote resolves to a file:// URL, which can only work with a
hint: standalone transfer agent.  See section "Using a Custom Transfer Type
hint: without the API server" in custom-transfers.md for details.

hint: The remote resolves to a file:// URL, which can only work with a
hint: standalone transfer agent.  See section "Using a Custom Transfer Type
hint: without the API server" in custom-transfers.md for details.
Downloading snapshot_test_goldens/goldens_64/MDCCardSnapshotTests/testDefaultCard_11_2@2x.png (1.9 KB)

hint: The remote resolves to a file:// URL, which can only work with a
hint: standalone transfer agent.  See section "Using a Custom Transfer Type
hint: without the API server" in custom-transfers.md for details.
Error downloading object: snapshot_test_goldens/goldens_64/MDCCardSnapshotTests/testDefaultCard_11_2@2x.png (96d48d5): Smudge error: Error downloading snapshot_test_goldens/goldens_64/MDCCardSnapshotTests/testDefaultCard_11_2@2x.png (96d48d51f415dc94427e49a361cf68cdadc86d0e00a6706894a7f82b5d13b086): batch request: missing protocol: "file:///Users/featherless/workbench/material-components-ios/.git/info/lfs"

Errors logged to /private/tmp/mdcios/mdc-ios/.git/lfs/logs/20181218T112727.676554.log
Use `git lfs logs last` to view the log.
error: external filter 'git-lfs filter-process' failed
fatal: 87e2596283dfea77c81ca83adaa53c62a2777dd3@2x.png: smudge filter lfs failed
warning: Clone succeeded, but checkout failed.
You can inspect what was checked out with 'git status'
and retry the checkout with 'git checkout -f HEAD'
```

material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,material-components/material-components-ios