Add debug ramdisk variant

A module will be installed to debug_ramdisk (or
debug_ramdisk/first_stage_ramdisk if recovery as boot is true) if
debug_ramdisk is set to true.

Bug: 184004542
Test: soong test
Change-Id: Ic5a4d27407e506fffa462de2149e0785f11b2ac7
diff --git a/cc/image.go b/cc/image.go
index ca00ac9..c331ae2 100644
--- a/cc/image.go
+++ b/cc/image.go
@@ -472,6 +472,10 @@
 	return c.Properties.VendorRamdiskVariantNeeded
 }
 
+func (c *Module) DebugRamdiskVariantNeeded(ctx android.BaseModuleContext) bool {
+	return false
+}
+
 func (c *Module) RecoveryVariantNeeded(ctx android.BaseModuleContext) bool {
 	return c.Properties.RecoveryVariantNeeded
 }