extra_apk_file is a new label only for APK files passed to microdroid.
microdroid_manager will create directories under /mnt/extra-apk/, and
zipfuse will mount APK block devices to the directories.
Currently only payload can read the files.
Bug: 205224817
Test: manually edit vm config and see APK files mounted
Change-Id: Ie5afb3156f22bb18979ec70904be675e8ff285a7
authfs_service is a binder service on microdroid. Upon a request by the
client, the service will create the mount directory, execute authfs to
mount the FUSE, and finally unmount and delete the mount directory.
authfs currently requires more privileges than it should, but it's ok
because the client owns the VM, and all input will be verified by
signatures. But there is plan to keep the privileges isoated in the
service (b/195554831).
Bug: 194717985
Bug: 195554831
Test: Start the service from init, use a test executable to call the
service API. Only observed denial from the test executable.
Change-Id: Ie53aa9e2796433fc3182357039d0b7ba1c0848ef