Remove ro.apex.updatable=false in GSI

Originally, GSI forced disable APEX and always contains apex
packages in flattern format. This patch remove the enforcement,
and APEX updateble is enabled according to ro.apex.updatable in
vendor.

Bug: 145245545
Test: build aosp_arm64-userdebug, check the property in system
Change-Id: I9cc943d7b2a30d037a2c1c137dad1233c1e3f57e
diff --git a/target/product/gsi_release.mk b/target/product/gsi_release.mk
index faaa935..aee7959 100644
--- a/target/product/gsi_release.mk
+++ b/target/product/gsi_release.mk
@@ -29,12 +29,6 @@
     system/product/% \
     system/system_ext/%
 
-
-# GSI doesn't support apex for now.
-# Properties set in product take precedence over those in vendor.
-PRODUCT_PRODUCT_PROPERTIES += \
-    ro.apex.updatable=false
-
 # Split selinux policy
 PRODUCT_FULL_TREBLE_OVERRIDE := true