Remove PRODUCT_AAPT2_CFLAGS and PRODUCT_AAPT_FLAGS

PRODUCT_AAPT2_CFLAGS and PRODUCT_AAPT_FLAGS are only used to pass
--pseudo-localize.  The flag doesn't need to be conditional on the
product, because the pseudo locale will be stripped out later if it
is not wanted.  Having it conditional on the product causes the
AAPT2-compiled resources to vary between products, which causes
unnecessary rebuilds when swithcing products.

Remove the variables, always add --pseudo-localize, and move
the AAPT2 compiled output to the common intermediates.

Test: m checkbuild
Change-Id: Iacc914114616b5bd19d9a1011802f4f9bca9bc19