Enable dynamic image size for all generic devices

We enabled the dynamic image for all generic_* BoardConfig.mk.
If a product makefile which use these BoardConfig.mk, it should
define PRODUCT_USE_DYNAMIC_PARTITION_SIZE to enable dynamic image.

This patch enable PRODUCT_USE_DYNAMIC_PARTITION_SIZE to product
`full` and `mainline_$arch`.

Bug: 71970853
Test: make -j PRODUCT-full-eng dist
Test: make -j PRODUCT-mainline_arm64-userdebug dist
Change-Id: I499b733638165306e3b0512859e205a1b36a9130