Don't generate recovery patch for A/B systems.

An A/B system that has a recovery image should not generate the recovery patch.
This change gates the creation of the recovery patch such that we create it
only when the recovery image exists and only for non-A/B systems.

Test: Build A/B system, verify that recovery patch is not present.
Bug: 144104493
Change-Id: Ib570c21b73912c4e4b7a964b192abc15fde9a753
diff --git a/core/Makefile b/core/Makefile
index 2879ab0..ea852e6 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -4348,10 +4348,12 @@
 	$(hide) cp $(PRODUCT_ODM_BASE_FS_PATH) \
 	  $(zip_root)/META/$(notdir $(PRODUCT_ODM_BASE_FS_PATH))
 endif
+ifneq ($(AB_OTA_UPDATER),true)
 ifneq ($(INSTALLED_RECOVERYIMAGE_TARGET),)
 	$(hide) PATH=$(INTERNAL_USERIMAGES_BINARY_PATHS):$$PATH MKBOOTIMG=$(MKBOOTIMG) \
 	    $(MAKE_RECOVERY_PATCH) $(zip_root) $(zip_root)
 endif
+endif
 ifeq ($(AB_OTA_UPDATER),true)
 	@# When using the A/B updater, include the updater config files in the zip.
 	$(hide) cp $(TOPDIR)system/update_engine/update_engine.conf $(zip_root)/META/update_engine_config.txt