Fix aosp_arm64 build error when `make ramdisk_debug`

Some targets have ramdisk.img but no boot.img, howerver,
ramdisk-debug.img only depends on boot.img. Fix this by making
ramdisk-debug.img depends on ramdisk.img.

Bug: 126493225
Test: make ramdisk_debug
Change-Id: I65120a3b3372712fafc26442354ee031eede0bd3
diff --git a/core/Makefile b/core/Makefile
index 7361550..d00f7bf 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -1982,9 +1982,14 @@
 
 $(INSTALLED_DEBUG_RAMDISK_TARGET): DEBUG_RAMDISK_SYNC_DIR := $(my_debug_ramdisk_sync_dir)
 $(INSTALLED_DEBUG_RAMDISK_TARGET): DEBUG_RAMDISK_ROOT_DIR := $(my_debug_ramdisk_root_dir)
-# We should have just depended on ramdisk.img or ramdisk-recovery.img.
-# But ramdisk-recovery.img is not a make target, so let's depend on the boot.img directly.
+
+ifeq ($(BOARD_USES_RECOVERY_AS_BOOT),true)
+# ramdisk-recovery.img isn't a make target, need to depend on boot.img if it's for recovery.
 $(INSTALLED_DEBUG_RAMDISK_TARGET): $(INSTALLED_BOOTIMAGE_TARGET)
+else
+# Depends on ramdisk.img, note that some target has ramdisk.img but no boot.img, e.g., emulator.
+$(INSTALLED_DEBUG_RAMDISK_TARGET): $(INSTALLED_RAMDISK_TARGET)
+endif # BOARD_USES_RECOVERY_AS_BOOT
 $(INSTALLED_DEBUG_RAMDISK_TARGET): $(MKBOOTFS) $(INTERNAL_DEBUG_RAMDISK_FILES) | $(MINIGZIP)
 	$(call pretty,"Target debug ram disk: $@")
 	mkdir -p $(TARGET_DEBUG_RAMDISK_OUT)