Small changes

- Disable generation of unused OTA to reduce compile time
- 17.1+: Disable APEX, breaks signing, and is also useless since no Play Store.
- 18.1: Fixup signing

Patches/LineageOS-18.1/android_build/0002-OTA_Keys.patch

@@ -0,0 +1,29 @@
+From 7cea4afe3e17c1dc8910c8ae9ad551bf280173ea Mon Sep 17 00:00:00 2001
+From: Tad <tad@spotco.us>
+Date: Wed, 31 Mar 2021 01:26:27 -0400
+Subject: [PATCH] Support OTA recovery key override
+
+Change-Id: I216c121a54331e9424dfc1543f85752b07229d9b
+---
+ core/product_config.mk | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/core/product_config.mk b/core/product_config.mk
+index a16af05cf..0152a3543 100644
+--- a/core/product_config.mk
++++ b/core/product_config.mk
+@@ -280,6 +280,11 @@ $(foreach pair,$(PRODUCT_UPDATABLE_BOOT_JARS), \
+ ENFORCE_SYSTEM_CERTIFICATE := $(PRODUCT_ENFORCE_ARTIFACT_SYSTEM_CERTIFICATE_REQUIREMENT)
+ ENFORCE_SYSTEM_CERTIFICATE_ALLOW_LIST := $(PRODUCT_ARTIFACT_SYSTEM_CERTIFICATE_REQUIREMENT_ALLOW_LIST)
+ 
++ifneq ($(OTA_KEY_OVERRIDE_DIR),)
++    OTA_PUBLIC_KEYS := $(OTA_KEY_OVERRIDE_DIR)/releasekey.x509.pem
++    PRODUCT_EXTRA_RECOVERY_KEYS := $(OTA_KEY_OVERRIDE_DIR)/extra
++endif
++
+ PRODUCT_OTA_PUBLIC_KEYS := $(sort $(PRODUCT_OTA_PUBLIC_KEYS))
+ PRODUCT_EXTRA_RECOVERY_KEYS := $(sort $(PRODUCT_EXTRA_RECOVERY_KEYS))
+ 
+-- 
+2.30.2
+