Revert^2 "Determine build_ota_package based on recovery.fstab install location"

This change resubmits https://r.android.com/3461419.

recovery_fstab can be installed even if is not defined via
TARGET_RECOVERY_FSTAB_GENRULE. This change modifies the conditional in
determining build_ota_package to take such scenarios into account.

Test: m otapackage
Change-Id: Id4cdd1b0d9953535cee9096047e432bcf8a0fa10
diff --git a/core/Makefile b/core/Makefile
index ada5be5..c4327fd 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -5651,7 +5651,9 @@
       endif
     endif # INSTALLED_BOOTIMAGE_TARGET == ""
     ifeq ($(recovery_fstab),)
-      build_ota_package := false
+      ifeq ($(filter $(TARGET_RECOVERY_ROOT_OUT)/system/etc/recovery.fstab,$(INTERNAL_RECOVERYIMAGE_FILES)),)
+        build_ota_package := false
+      endif
     endif
   endif # PRODUCT_BUILD_GENERIC_OTA_PACKAGE