Enable windows target

`//tools/apksig` build targets will soon depend
on this, and windows must be enabled (transitively)
on all dependencies.

Bug: 319296492
Test: TH
Change-Id: Ifbc1e4b0a0e0938385f6811ff12987f14a7f7ae2
diff --git a/Android.bp b/Android.bp
index 492d574..b0c8010 100644
--- a/Android.bp
+++ b/Android.bp
@@ -42,6 +42,11 @@
         "//apex_available:anyapex",
         "//apex_available:platform",
     ],
+    target: {
+        windows: {
+            enabled: true,
+        },
+    },
 }
 
 java_import {