Revert "Retire mainline.mk"

This reverts commit 60c00649026397de2259e94fb71e8c05b3ebe3c5.

Reason for revert: build breakages

Change-Id: Ie8304d1979c50578901efed77fb31281c336505c
Fixes: 157548597
diff --git a/target/product/mainline.mk b/target/product/mainline.mk
new file mode 100644
index 0000000..22436e6
--- /dev/null
+++ b/target/product/mainline.mk
@@ -0,0 +1,39 @@
+#
+# 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.
+#
+
+# This makefile is intended to serve as a base for completely AOSP based
+# mainline devices, It contain the mainline system partition and sensible
+# defaults for the system_ext, product and vendor partitions.
+$(call inherit-product, $(SRC_TARGET_DIR)/product/mainline_system.mk)
+
+$(call inherit-product, $(SRC_TARGET_DIR)/product/handheld_system_ext.mk)
+$(call inherit-product, $(SRC_TARGET_DIR)/product/handheld_vendor.mk)
+$(call inherit-product, $(SRC_TARGET_DIR)/product/handheld_product.mk)
+$(call inherit-product, $(SRC_TARGET_DIR)/product/telephony_system_ext.mk)
+$(call inherit-product, $(SRC_TARGET_DIR)/product/telephony_vendor.mk)
+$(call inherit-product, $(SRC_TARGET_DIR)/product/telephony_product.mk)
+
+$(call inherit-product, frameworks/base/data/sounds/AllAudio.mk)
+
+PRODUCT_PROPERTY_OVERRIDES += \
+    ro.config.ringtone=Ring_Synth_04.ogg \
+    ro.com.android.dataroaming=true \
+
+PRODUCT_PACKAGES += \
+    PhotoTable \
+    WallpaperPicker \
+
+PRODUCT_COPY_FILES += device/sample/etc/apns-full-conf.xml:$(TARGET_COPY_OUT_PRODUCT)/etc/apns-conf.xml