Fix phony target warning for LOCAL_ROTATION_MIN_SDK_VERSION.

Test: m signapk
Test: make GoogleRestorePrebuilt apksigner
Test: Add LOCAL_ROTATION_MIN_SDK_VERSION := 33 to vendor/unbundled_google/packages/GoogleRestorePrebuilt/Android.mk and run both commands above again -- no phony target warnings

Bug: 197787352

Change-Id: If106113b6557ad1ecf24e2778bd38e7cb30e39ca
diff --git a/core/app_prebuilt_internal.mk b/core/app_prebuilt_internal.mk
index f5d213e..4586f35 100644
--- a/core/app_prebuilt_internal.mk
+++ b/core/app_prebuilt_internal.mk
@@ -128,6 +128,9 @@
     LOCAL_CERTIFICATE := $(dir $(DEFAULT_SYSTEM_DEV_CERTIFICATE))$(LOCAL_CERTIFICATE)
   endif
 
+  # NOTE(ruperts): Consider moving the logic below out of a conditional,
+  # to avoid the possibility of silently ignoring user settings.
+
   PACKAGES.$(LOCAL_MODULE).PRIVATE_KEY := $(LOCAL_CERTIFICATE).pk8
   PACKAGES.$(LOCAL_MODULE).CERTIFICATE := $(LOCAL_CERTIFICATE).x509.pem
   PACKAGES := $(PACKAGES) $(LOCAL_MODULE)
@@ -143,7 +146,6 @@
   $(built_module): $(LOCAL_CERTIFICATE_LINEAGE)
   $(built_module): PRIVATE_CERTIFICATE_LINEAGE := $(LOCAL_CERTIFICATE_LINEAGE)
 
-  $(built_module): $(LOCAL_ROTATION_MIN_SDK_VERSION)
   $(built_module): PRIVATE_ROTATION_MIN_SDK_VERSION := $(LOCAL_ROTATION_MIN_SDK_VERSION)
 endif