Ban ELF prebuilts in PRODUCT_COPY_FILES

ELF prebuilts in PRODUCT_COPY_FILES are an build error.
Define prebuilt modules and add them to PRODUCT_PACKAGES instead.

To triage any build break caused by this change, temporarily opt out
this check by setting
BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES := true in BoardConfig.mk.

Bug: 140560012
Test: build_test & verify that either PRODUCT_COPY_FILES has no ELF \
      prebuilt or BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES is true
Change-Id: I9dcbe7b68c38fc23dac91fe5751cbc478105656e