Move/dedupe some host path functions in package_ctx.go.

These functions don't need a PackageContext object.

Test: m
Bug: 145934348
Change-Id: Ia1da2c76cbad292f9ca79617199b2b5b6b265568

apex/builder.go

@@ -43,7 +43,7 @@ func init() {
 			if !ctx.Config().FrameworksBaseDirExists(ctx) {
 				return filepath.Join(prebuiltDir, runtime.GOOS, "bin", tool)
 			} else {
-				return pctx.HostBinToolPath(ctx, tool).String()
+				return ctx.Config().HostToolPath(ctx, tool).String()
 			}
 		})
 	}