Add RuleBuilder helper functions for built and prebuilt tools

Replace the common pattern of:
cmd.Tool(ctx.Config().HostToolPath(ctx, "tool"))
with:
cmd.BuiltTool("tool")

And similarly for PrebuiltBuildTool.

Test: m checkbuild
Change-Id: I7d63188505362c7df6a3b3e7330b4a2cca5a2409
diff --git a/java/app.go b/java/app.go
index 3442658..a679e88 100644
--- a/java/app.go
+++ b/java/app.go
@@ -816,7 +816,7 @@
 	rule := android.NewRuleBuilder()
 	rule.Command().
 		Textf(`if (zipinfo %s 'lib/*.so' 2>/dev/null | grep -v ' stor ' >/dev/null) ; then`, inputPath).
-		Tool(ctx.Config().HostToolPath(ctx, "zip2zip")).
+		BuiltTool(ctx, "zip2zip").
 		FlagWithInput("-i ", inputPath).
 		FlagWithOutput("-o ", outputPath).
 		FlagWithArg("-0 ", "'lib/**/*.so'").
@@ -843,7 +843,7 @@
 	rule := android.NewRuleBuilder()
 	rule.Command().
 		Textf(`if (zipinfo %s '*.dex' 2>/dev/null | grep -v ' stor ' >/dev/null) ; then`, inputPath).
-		Tool(ctx.Config().HostToolPath(ctx, "zip2zip")).
+		BuiltTool(ctx, "zip2zip").
 		FlagWithInput("-i ", inputPath).
 		FlagWithOutput("-o ", outputPath).
 		FlagWithArg("-0 ", "'classes*.dex'").
@@ -1067,7 +1067,7 @@
 	outputFile := android.PathForModuleOut(ctx, "manifest_check", "AndroidManifest.xml")
 
 	rule := android.NewRuleBuilder()
-	cmd := rule.Command().Tool(ctx.Config().HostToolPath(ctx, "manifest_check")).
+	cmd := rule.Command().BuiltTool(ctx, "manifest_check").
 		Flag("--enforce-uses-libraries").
 		Input(manifest).
 		FlagWithOutput("-o ", outputFile)