Make gl_headers available to com.android.virt apex

Needed to make crosvm vendor available

Bug: 309149829
Test: build aosp_cf_x86_64_phone_trusty_vm-userdebug
Change-Id: I1c50d40411d462a32e6b159f965be6f30317d406
diff --git a/opengl/Android.bp b/opengl/Android.bp
index b15694b..4454f36 100644
--- a/opengl/Android.bp
+++ b/opengl/Android.bp
@@ -72,6 +72,10 @@
     llndk: {
         llndk_headers: true,
     },
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.virt",
+    ],
 }
 
 subdirs = [