Clean up unused components [2/3]

* PRODUCT_PRIVATE_KEY seems to be used nowhere.
* AB_OTA_POSTINSTALL_CONFIG is for Q launch devices.
* TARGET_ENABLE_QC_AV_ENHANCEMENTS dependency is now dropped.

Issue: FP3-A11#310
Change-Id: Idcbc2d08850b3ff34fbc3a933134c30f77b88133
diff --git a/device.mk b/device.mk
index 9e4b875..256df5a 100644
--- a/device.mk
+++ b/device.mk
@@ -35,11 +35,8 @@
 # targeting the same model with all of them.
 PRODUCT_BUILD_PROP_OVERRIDES += PRODUCT_MODEL=FP3 PRODUCT_NAME=FP3 TARGET_PRODUCT=FP3
 
-# vendor/qcom/proprietary/common/config/device-vendor.mk --> PRODUCT_LIST
-TARGET_BASE_PRODUCT := FP3
-TARGET_VENDOR := fairphone
 
-TARGET_SYSTEM_PROP := device/$(TARGET_VENDOR)/$(PRODUCT_NAME)/system.prop
+TARGET_SYSTEM_PROP := $(FP_PATH)/system.prop
 
 # Define the build number based on the product flavour and on the build manifest
 # revision
@@ -77,14 +74,7 @@
 	vendor
 
 
-AB_OTA_POSTINSTALL_CONFIG += \
-	RUN_POSTINSTALL_vendor=true \
-	POSTINSTALL_PATH_vendor=bin/checkpoint_gc \
-	FILESYSTEM_TYPE_vendor=ext4 \
-	POSTINSTALL_OPTIONAL_vendor=true
-
 PRODUCT_PACKAGES += \
-	checkpoint_gc \
 	update_engine_sideload
 
 
@@ -108,10 +98,6 @@
 
 
 # Audio
-# AV Enhancement
-TARGET_ENABLE_QC_AV_ENHANCEMENTS := true
-
-
 PRODUCT_PACKAGES += \
 	android.hardware.audio@6.0 \
 	android.hardware.audio.common@6.0 \