Remove the hack that uses INSTALLED_RAMDISK_TARGET as INSTALLED_BOOTIMAGE_TARGET.

This also fixes the emulator build issue with `BOARFD_AVB_ENABLE := true`.

Bug: 78113934
Test: `m dist` with emulator builds.
Test: `m dist` with aosp_taimen-userdebug
Change-Id: I2089e0ab15885b4cfc16d4a7e8be3dd0b60ef46f
diff --git a/core/main.mk b/core/main.mk
index 678bc98..91028e5 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -1221,6 +1221,7 @@
 .PHONY: droidcore
 droidcore: files \
     systemimage \
+    $(INSTALLED_RAMDISK_TARGET) \
     $(INSTALLED_BOOTIMAGE_TARGET) \
     $(INSTALLED_RECOVERYIMAGE_TARGET) \
     $(INSTALLED_VBMETAIMAGE_TARGET) \