Set file system types for mainline_arm64 partitions

This config was in a weird state where it sets the OUT
directory for these partitions but not the file system
type. Within the build system, both of these variables
are used interchangeably to check whether these partitions
are expected to be present.

A typical mainline device is expected to /vendor and
/product, so just add these.

Bug: 120974093
Test: make
Change-Id: I803d7afdcadc37e4384ae80f08bc1c8db535d2f4