Include jacoco in the ART boot image if EMMA_INSTRUMENT_FRAMEWORK=true.

Test: aosp_walleye-userdebug boots.

Test: Coverage build boots:
  $ lunch aosp_walleye-userdebug
  $ cd $ANDROID_BUILD_TOP
  $ build/soong/soong_ui.bash --make-mode droid \
    SKIP_ABI_CHECKS=true \
    TARGET_PRODUCT=aosp_walleye \
    TARGET_BUILD_VARIANT=userdebug \
    EMMA_INSTRUMENT=true \
    NATIVE_COVERAGE=true
  $ adb reboot bootloader && fastboot flashall -w

Test: Coverage build with framework coverage boots:
  $ lunch aosp_walleye-userdebug
  $ cd $ANDROID_BUILD_TOP
  $ build/soong/soong_ui.bash --make-mode droid \
    SKIP_ABI_CHECKS=true \
    TARGET_PRODUCT=aosp_walleye \
    TARGET_BUILD_VARIANT=userdebug \
    EMMA_INSTRUMENT=true \
    EMMA_INSTRUMENT_FRAMEWORK=true \
    NATIVE_COVERAGE=true
  $ adb reboot bootloader && fastboot flashall -w

Test: Static coverage build with framework coverage boots:
  $ lunch aosp_walleye-userdebug
  $ cd $ANDROID_BUILD_TOP
  $ build/soong/soong_ui.bash --make-mode droid \
    SKIP_ABI_CHECKS=true \
    TARGET_PRODUCT=aosp_walleye \
    TARGET_BUILD_VARIANT=userdebug \
    EMMA_INSTRUMENT=true \
    EMMA_INSTRUMENT_FRAMEWORK=true \
    EMMA_INSTRUMENT_STATIC=true \
    NATIVE_COVERAGE=true
  $ adb reboot bootloader && fastboot flashall -w

Change-Id: Iaa198b8505aaff36e6685559642ff721637ce55f