Add support for auto-generated characteristics RRO

Setting use_rro_for_product will automatically generate an RRO package
which contains resources with 'product="{PRODUCT_CHARACTERISTICS}"'. The
RRO package will be installed to /product partition. The app will be
compiled with '--product default', making the app identical to all
targets.

Motivation for this change is to minimize divergence of system.img.

Bug: 294799593
Test: boot and idmap2 dump
Change-Id: I549c2589c69eab7a1568510a7d1ff0c8a003f7ea