Revert "Unset PRODUCT_INSTALL_DEBUG_POLICY_TO_SYSTEM_EXT for gsi_car_${arch}.mk"

This reverts commit 9404c159499521c19ab29018da59cae12a4d92f3.

Reason for revert: b:213963330

Bug: 213963330
Test: build gsi_car_arm64
Change-Id: Ia8d34fa9b6b92052416239934480ef021d906401
(cherry picked from commit 6c0452e91ef4a206c5f522aed92bf12f76b82d76)
diff --git a/gsi_car_arm64.mk b/gsi_car_arm64.mk
index fcda6b2..0977da4 100644
--- a/gsi_car_arm64.mk
+++ b/gsi_car_arm64.mk
@@ -16,10 +16,6 @@
 $(call inherit-product, device/generic/car/gsi_car_base.mk)
 $(call inherit-product, device/generic/common/gsi_arm64.mk)
 
-# This option is specific to the phone GSI, so clear this option after
-# gsi_arm64.mk is inherited.
-PRODUCT_INSTALL_DEBUG_POLICY_TO_SYSTEM_EXT :=
-
 PRODUCT_NAME := gsi_car_arm64
 PRODUCT_DEVICE := generic_arm64
 PRODUCT_BRAND := Android
diff --git a/gsi_car_x86_64.mk b/gsi_car_x86_64.mk
index 519deef..378fa5c 100644
--- a/gsi_car_x86_64.mk
+++ b/gsi_car_x86_64.mk
@@ -16,10 +16,6 @@
 $(call inherit-product, device/generic/car/gsi_car_base.mk)
 $(call inherit-product, device/generic/common/gsi_x86_64.mk)
 
-# This option is specific to the phone GSI, so clear this option after
-# gsi_x86_64.mk is inherited.
-PRODUCT_INSTALL_DEBUG_POLICY_TO_SYSTEM_EXT :=
-
 PRODUCT_NAME := gsi_car_x86_64
 PRODUCT_DEVICE := generic_x86_64
 PRODUCT_BRAND := Android