Cleanup RRO enforcement in mainline device makefiles

Now that mainline_system.mk enforces /system module RRO, there's no need
to specify RRO enforcement in each of the divice makefiles.

Bug: 141971626
Test: TH
Change-Id: I85c5db9f91dd14171e88fd53a8237b07c31620da

device.mk

diff --git a/device.mk b/device.mk
index dc51d98..7a400a6 100644
--- a/device.mk
+++ b/device.mk
@@ -678,8 +678,6 @@
 PRODUCT_PACKAGES += \
     vndk-sp
 
-PRODUCT_ENFORCE_RRO_TARGETS := *
-
 # Override heap growth limit due to high display density on device
 PRODUCT_PROPERTY_OVERRIDES += \
     dalvik.vm.heapgrowthlimit=256m