Unconditionally generate build_manifest.pb

Previously, the file is generated only if there's interesting files. The
condition isn't really desirable in build rule evaluation, and makes it
a bit harder to handle in the consuming code.

Bug: 256793394
Test: atest ComposHostTestCases odsign_e2e_tests
Change-Id: I87b257b6ce6ab0ba565378c885adf35c1d25235b
diff --git a/core/Makefile b/core/Makefile
index 6f9a500..f237724 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -2987,12 +2987,10 @@
     $$(fsverity-metadata-targets-$(2))
 	rm -rf $$(PRIVATE_ASSETS)
 	mkdir -p $$(PRIVATE_ASSETS)
-ifdef fsverity-metadata-targets-$(2)
 	$$< --fsverity-path $$(PRIVATE_FSVERITY) \
 	    --base-dir $$(PRODUCT_OUT) \
 	    --output $$(PRIVATE_ASSETS)/build_manifest.pb \
 	    $$(PRIVATE_INPUTS)
-endif  # fsverity-metadata-targets-$(2)
 	$$(PRIVATE_AAPT2) link -o $$@ \
 	    -A $$(PRIVATE_ASSETS) \
 	    -I $$(PRIVATE_FRAMEWORK_RES) \