ANDROID: microdroid: disable unneeded networking options

Disable all the networking options except UNIX domain sockets, virtio
vsockets, and basic support for TCP/IP (required by SECURITY_SELINUX).
Those are the only parts that should be needed in microdroid.

arm64: This shrinks Image.gz from 5530232 bytes to 5270262 bytes.

Bug: 391456174
Change-Id: If7b2e11416bd4eac0de6703d50b6debd697cd6c8
Signed-off-by: Eric Biggers <ebiggers@google.com>