Set allow list for generic ramdisk

Devices that uses generic ramdisk must inherit from generic_ramdisk.mk.
This makefile ensures that only a set of files can be installed to the
ramdisk. Other files must be installed to the vendor-ramdisk.

Let aosp_arm64 use this makefile.

Fixes: 173742069
Test: manual
Change-Id: Ib2a4a208deaf2f4d707bec256207b4b8479a601a
(cherry picked from commit bc9608c4c3f3cd0ac3f29863209c80fcfe4e2f7f)
diff --git a/target/board/generic_arm64/device.mk b/target/board/generic_arm64/device.mk
index 7c19279..930083c 100644
--- a/target/board/generic_arm64/device.mk
+++ b/target/board/generic_arm64/device.mk
@@ -32,3 +32,5 @@
 
 PRODUCT_BUILD_VENDOR_BOOT_IMAGE := false
 PRODUCT_BUILD_RECOVERY_IMAGE := false
+
+$(call inherit-product, $(SRC_TARGET_DIR)/product/generic_ramdisk.mk)
diff --git a/target/product/generic_ramdisk.mk b/target/product/generic_ramdisk.mk
new file mode 100644
index 0000000..0698648
--- /dev/null
+++ b/target/product/generic_ramdisk.mk
@@ -0,0 +1,42 @@
+#
+# Copyright (C) 2020 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.
+#
+
+# This makefile installs contents of the generic ramdisk.
+# Inherit from this makefile to declare that this product uses generic ramdisk.
+# This makefile checks that other makefiles must not install things to the
+# ramdisk.
+
+PRODUCT_NAME := generic_ramdisk
+PRODUCT_BRAND := generic
+
+# Ramdisk
+PRODUCT_PACKAGES += \
+    init_first_stage \
+
+# Debug ramdisk
+PRODUCT_PACKAGES += \
+    userdebug_plat_sepolicy.cil \
+
+_my_paths := \
+    $(TARGET_COPY_OUT_RAMDISK) \
+    $(TARGET_COPY_OUT_DEBUG_RAMDISK) \
+    system/usr/share/zoneinfo/tz_version \
+    system/usr/share/zoneinfo/tzdata \
+
+# We use the "relaxed" version here because tzdata / tz_version is only produced
+# by this makefile on a subset of devices.
+# TODO: remove this
+$(call require-artifacts-in-path-relaxed, $(_my_paths), )