Use PathForModuleOutput instead of PathForPhony

Later breaks some build flavours ¯\_(ツ)_/¯

Bug: 140467657
Test: soong_ui.bash --make-mode vts dist DIST_DIR=/tmp/dist-dir/ TARGET_PRODUCT=aosp_arm64 WITH_DEXPREOPT_BOOT_IMG_AND_SYSTEM_SERVER_ONLY=true BUILD_GOOGLE_VTS=true TARGET_BUILD_VARIANT=eng NATIVE_COVERAGE=true COVERAGE_PATHS="test/vts/hals/light" ENABLE_TREBLE=true
Change-Id: I0cb5754cb93551f2ed66d804f36019b037ccd871
diff --git a/apex/apex.go b/apex/apex.go
index f8eca8e..9c9d6ae 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -1192,7 +1192,7 @@
 		implicitInputs = append(implicitInputs, imageContentFile)
 		whitelistedFilesFile := android.PathForModuleSrc(ctx, proptools.String(a.properties.Whitelisted_files))
 
-		phonyOutput := android.PathForPhony(ctx, ctx.ModuleName()+"-diff-phony-output")
+		phonyOutput := android.PathForModuleOut(ctx, ctx.ModuleName()+"-diff-phony-output")
 		ctx.Build(pctx, android.BuildParams{
 			Rule:        diffApexContentRule,
 			Implicits:   implicitInputs,