Check ELF prebuilts in PRODUCT_COPY_FILES

Add a check to ban ELF prebuilts in PRODUCT_COPY_FILES.
ELF prebuilts should be defined properly by cc_prebuilt_library_shared
and cc_prebuilt_binary so that the build system can keep track of the
file dependencies.

To opt in this check, set this option in BoardConfig.mk:
  BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES := false

After all devices that have ELF prebuilts in PRODUCT_COPY_FILES are
tagged with BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES := true flip
BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES to default false.

After a device is cleaned up, remove its
BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES := true setting.

Bug: 140560012
Test: Set BUILD_BROKEN_ELF_PREBUILT_PRODUCT_COPY_FILES := false
Test: m # Should report any ELF prebuilt error in PRODUCT_COPY_FILES
Change-Id: Id75dac9417aed9baa7c5e9388430ff9369cf9b4f