libartpalette: Fix non-existent required dependency

HOST_CROSS module host_cross_libartpalette has non-existent required: host_cross_libartpalette-system
HOST_CROSS module host_cross_libartpalette_64 has non-existent required: host_cross_libartpalette-system

Only specify required dependency for device variant because only device
variant is dlopen()-ing libartpalette-system.so

Bug: 7456955
Test: TH presubmit
Test: m com.android.art.debug # libartpalette-system is also installed
Change-Id: I04aac73ba769d78ebb774ec5a6c243628e23d70f
1 file changed