Remove unnecessary inheritance layer between aliases.

The extra inheritance layer may cause multiple
PRODUCT_DEVICE/PRODUCT_BRAND values for a product if it doesn't
explicitly override them, eg. gms.
The full_* are deprecated product names. We keep them just for backward
compatibility, for some tools may still use the full_* product names.

Bug: 25611987
Change-Id: I7ecebd422754c3ceb16507b8d9ced65d533fe7c3