Add Android Go defaults make file

Go devices should inherit this file to provide good default settings
for providing the best experience on Android Go devices.

Bug: 67374015
Test: make and flash

Change-Id: I55f22735c70f69309ec77e5c3055e6747546c79a

target/product/go_defaults.mk

@@ -0,0 +1,57 @@
+#
+# Copyright (C) 2017 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.
+#
+
+# Sets Android Go recommended default values for propreties.
+
+# Set lowram options
+PRODUCT_PROPERTY_OVERRIDES += \
+     ro.config.low_ram=true \
+     ro.lmk.critical_upgrade=true \
+     ro.lmk.upgrade_pressure=40
+
+# set threshold to filter unused apps
+PRODUCT_PROPERTY_OVERRIDES += \
+     pm.dexopt.downgrade_after_inactive_days=10
+
+
+# Speed profile services and wifi-service to reduce RAM and storage.
+PRODUCT_SYSTEM_SERVER_COMPILER_FILTER := speed-profile
+
+# Always preopt extracted APKs to prevent extracting out of the APK for gms
+# modules.
+PRODUCT_ALWAYS_PREOPT_EXTRACTED_APK := true
+
+# Use a profile based boot image for this device. Note that this is currently a
+# generic profile and not Android Go optimized.
+PRODUCT_USE_PROFILE_FOR_BOOT_IMAGE := true
+PRODUCT_DEX_PREOPT_BOOT_IMAGE_PROFILE_LOCATION := frameworks/base/config/boot-image-profile.txt
+
+# set the compiler filter for shared apks to quicken.
+# Rationale: speed has a lot of dex code expansion, it uses more ram and space
+# compared to quicken. Using quicken for shared APKs on Go devices may save RAM.
+# Note that this is a trade-off: here we trade clean pages for dirty pages,
+# extra cpu and battery. That's because the quicken files will be jit-ed in all
+# the processes that load of shared apk and the code cache is not shared.
+# Some notable apps that will be affected by this are gms and chrome.
+# b/65591595.
+PRODUCT_PROPERTY_OVERRIDES += \
+     pm.dexopt.shared=quicken
+
+# Default heap sizes. Allow up to 256m for large heaps to make sure a single app
+# doesn't take all of the RAM.
+PRODUCT_PROPERTY_OVERRIDES += dalvik.vm.heapgrowthlimit=128m
+PRODUCT_PROPERTY_OVERRIDES += dalvik.vm.heapsize=256m
+