Make apex availability of PlatformProperties explicit

The availability to com.android.wifi was done implicitly using a baseline map in
build/soong/apex/apex.go. Make this explicit in Android.bp

Bug: 281077552
Test: m nothing
Change-Id: Ib9e981b932b1daaf34c4df51ae8be7c624afb58b

srcs/Android.bp

diff --git a/srcs/Android.bp b/srcs/Android.bp
index d155b38..344bc85 100644
--- a/srcs/Android.bp
+++ b/srcs/Android.bp
@@ -32,6 +32,7 @@
         "com.android.media.swcodec",
         "com.android.tethering",
         "com.android.virt",
+        "com.android.wifi",
     ],
     cpp: {
         min_sdk_version: "S",