Add updatable_apex.mk

The product abstracts configs that need to be set to support updating of
APEXes.

Bug: 130418467
Test: m
Test: adb shell getprop ro.apex.updatable in Pixel 2 and 3
Test: adb shell /system/apex/com.android.apex.cts.shim.apex exists.
Merged-In: Idb44388a0cf6338f8b4500a1d0d2762ed59476bf
Change-Id: Idb44388a0cf6338f8b4500a1d0d2762ed59476bf
(cherry picked from commit fa51bedf8b)

target/product/mainline_system.mk

@@ -18,6 +18,8 @@
 $(call inherit-product, $(SRC_TARGET_DIR)/product/handheld_system.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/product/telephony_system.mk)
 $(call inherit-product, $(SRC_TARGET_DIR)/product/languages_default.mk)
+# Enable updating of APEXes
+$(call inherit-product, $(SRC_TARGET_DIR)/product/updatable_apex.mk)
 # Add adb keys to debuggable AOSP builds (if they exist)
 $(call inherit-product-if-exists, vendor/google/security/adb/vendor_key.mk)
 

target/product/updatable_apex.mk

@@ -0,0 +1,20 @@
+#
+# Copyright (C) 2019 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Inherit this when the target needs to support updating APEXes
+
+PRODUCT_PROPERTY_OVERRIDES := ro.apex.updatable=true
+PRODUCT_PACKAGES := com.android.apex.cts.shim.v1_prebuilt