Move hidden API metadata file rule to platform_bootclasspath

This change moves the monolithic hidden API index file creation rule
from the hiddenAPISingleton into the platform_bootclasspath.

Bug: 179354495
Test: verified that the out/soong/hiddenapi/... files are unchanged
      by this change
Change-Id: Ib25be3618e30a83dc2929a18062eb58eefdabefb
diff --git a/java/hiddenapi_singleton.go b/java/hiddenapi_singleton.go
index 8f3a3ba..ed0b722 100644
--- a/java/hiddenapi_singleton.go
+++ b/java/hiddenapi_singleton.go
@@ -115,7 +115,7 @@
 }
 
 type hiddenAPISingleton struct {
-	flags, metadata android.Path
+	flags android.Path
 }
 
 // hiddenAPI singleton rules
@@ -144,24 +144,18 @@
 	// These rules depend on files located in frameworks/base, skip them if running in a tree that doesn't have them.
 	if ctx.Config().FrameworksBaseDirExists(ctx) {
 		h.flags = flagsRule(ctx)
-		h.metadata = metadataRule(ctx)
 	} else {
 		h.flags = emptyFlagsRule(ctx)
 	}
 }
 
 // Export paths to Make.  INTERNAL_PLATFORM_HIDDENAPI_FLAGS is used by Make rules in art/ and cts/.
-// Both paths are used to call dist-for-goals.
 func (h *hiddenAPISingleton) MakeVars(ctx android.MakeVarsContext) {
 	if ctx.Config().IsEnvTrue("UNSAFE_DISABLE_HIDDENAPI_FLAGS") {
 		return
 	}
 
 	ctx.Strict("INTERNAL_PLATFORM_HIDDENAPI_FLAGS", h.flags.String())
-
-	if h.metadata != nil {
-		ctx.Strict("INTERNAL_PLATFORM_HIDDENAPI_GREYLIST_METADATA", h.metadata.String())
-	}
 }
 
 // stubFlagsRule creates the rule to build hiddenapi-stub-flags.txt out of dex jars from stub modules and boot image
@@ -354,34 +348,6 @@
 	return outputPath
 }
 
-// metadataRule creates a rule to build hiddenapi-unsupported.csv out of the metadata.csv files generated for boot image
-// modules.
-func metadataRule(ctx android.SingletonContext) android.Path {
-	var metadataCSV android.Paths
-
-	ctx.VisitAllModules(func(module android.Module) {
-		if h, ok := module.(hiddenAPIIntf); ok {
-			if csv := h.metadataCSV(); csv != nil {
-				metadataCSV = append(metadataCSV, csv)
-			}
-		}
-	})
-
-	rule := android.NewRuleBuilder(pctx, ctx)
-
-	outputPath := hiddenAPISingletonPaths(ctx).metadata
-
-	rule.Command().
-		BuiltTool("merge_csv").
-		Flag("--key_field signature").
-		FlagWithOutput("--output=", outputPath).
-		Inputs(metadataCSV)
-
-	rule.Build("hiddenAPIGreylistMetadataFile", "hiddenapi greylist metadata")
-
-	return outputPath
-}
-
 // commitChangeForRestat adds a command to a rule that updates outputPath from tempPath if they are different.  It
 // also marks the rule as restat and marks the tempPath as a temporary file that should not be considered an output of
 // the rule.