Preopt SystemUI for AOSP builds.

Bug: 232860596
Test: See no dex2oat invocation on the first boot.
Change-Id: I21b99fac3934060d27fad7323979cbb5f0ed28e8
(cherry picked from commit 1346647ab4b40afb9d0e737df2ec0cf0f12c2c4d)
diff --git a/device.mk b/device.mk
index c449d89..c4701dd 100644
--- a/device.mk
+++ b/device.mk
@@ -451,6 +451,10 @@
 PRODUCT_VENDOR_PROPERTIES += ro.telephony.iwlan_operation_mode=legacy
 
 
+# Preopt SystemUI
+PRODUCT_DEXPREOPT_SPEED_APPS += SystemUI  # For AOSP
+
+
 # Display
 PRODUCT_PACKAGES += \
 	android.hardware.graphics.allocator@2.0-impl \