Revert "Build OTA when boot image exists even without kernel or recovery fstab"

This reverts commit ff2e24d6f96160730c9a2d4e92a486d96b8788cb.

Reason for revert: breaks build

Bug: 194018054
Change-Id: Ia7f0436d21dc07143f7fae6f90a73bb4f730e98d
diff --git a/core/Makefile b/core/Makefile
index 9e252c8..aaefacd 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -4210,25 +4210,16 @@
   ifeq ($(TARGET_PRODUCT),sdk)
     build_ota_package := false
   endif
-  # A target without a kernel or recovery fstab may be one of the following:
-  # - A generic target. In this case, the OTA package usually isn't built.
-  #   PRODUCT_BUILD_GENERIC_OTA_PACKAGE may be set to true to force OTA package
-  #   generation.
-  # - A real device target, with TARGET_NO_KERNEL set to true and
-  #   BOARD_PREBUILT_BOOTIMAGE set. In this case, it is valid to generate
-  #   an OTA package.
   ifneq ($(PRODUCT_BUILD_GENERIC_OTA_PACKAGE),true)
     ifneq ($(filter generic%,$(TARGET_DEVICE)),)
       build_ota_package := false
     endif
-    ifeq ($(INSTALLED_BOOTIMAGE_TARGET),)
-      ifeq ($(TARGET_NO_KERNEL),true)
-        build_ota_package := false
-      endif
-      ifeq ($(recovery_fstab),)
-        build_ota_package := false
-      endif
-    endif # INSTALLED_BOOTIMAGE_TARGET == ""
+    ifeq ($(TARGET_NO_KERNEL),true)
+      build_ota_package := false
+    endif
+    ifeq ($(recovery_fstab),)
+      build_ota_package := false
+    endif
   endif # PRODUCT_BUILD_GENERIC_OTA_PACKAGE
 
   # Set build_otatools_package, and allow opt-out below.