Clear apex.go entries for bluetooth libs

The module availability to Bluetooth is currently hard-coded in apex.go.
We are in the process of cleaning the apex.go by adding the availability
in each required module

Test: Build + TH + boot phone & use bluetooth
Bug: 216433795
Change-Id: Ie315d6b91ad41c9f97e3d5939e7624cc29d34dcf
diff --git a/Android.bp b/Android.bp
index aada4d9..3a61289 100644
--- a/Android.bp
+++ b/Android.bp
@@ -868,6 +868,10 @@
             ],
         },
     },
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.bluetooth",
+    ],
     min_sdk_version: "30",
 }