[PATCH v2] AOSP: erofs-utils: add fs_config support

[Gao Xiang]

On Tue, Sep 29, 2020 at 01:13:02PM +0800, Gao Xiang wrote:
> So that mkfs can directly generate images with fs_config.
> All code for AOSP is wraped up with WITH_ANDROID macro.
> 
> Signed-off-by: Gao Xiang <hsiangkao at aol.com>
> ---
> changes since v1:
>  - fix compile issues on Android / Linux build;
>  - tested with Android system booting;

Guifu, some feedback on this?
I'd like to merge it for AOSP preparation.