Revert "Remove Core Library JARs from `/system/framework`."

This reverts commit 3ec9ff6b.

Reason for revert: This change breaks coverage builds (b/143304991)

Change-Id: Ia1a41ea75d1539efeb33b7cdea84516e402b6e00
Test: Device boot test
Test: Check that:
        export EMMA_INSTRUMENT=true
        && unset EMMA_INSTRUMENT_STATIC
        && m installclean
        && m systemimage
      generates a system image that contains these files:
        /system/framework/apex-jacocoagent.vdex
        /system/framework/boot-jacocoagent.vdex
        /system/framework/jacocoagent.jar
        /system/framework/<arch>/apex-jacocoagent.art
        /system/framework/<arch>/apex-jacocoagent.oat
        /system/framework/<arch>/apex-jacocoagent.vdex
        /system/framework/<arch>/boot-jacocoagent.art
        /system/framework/<arch>/boot-jacocoagent.oat
        /system/framework/<arch>/boot-jacocoagent.vdex
Test: Test: Run test ATP test avd/avd_boot_health_check on build target
      cf_x86_phone-userdebug_coverage
Bug: 142944799
Bug: 143304991