Disable libbinder darwin builds

libbinder makes heavy use of linux headers, so it won't build on a mac.
This gives us cleaner errors when a mac target depends on it. Instead of
seeing libbinder build breakages, we will see the missing dependency
error.

Exempt-From-Owner-Approval: fixing build breakage

Test: none
Bug: 172023026
Change-Id: I4eadf2c9c09599b5d1bcafdb7d8559946c854e49
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index d363ee9..e6071a0 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -31,6 +31,11 @@
         "libutils_headers",
     ],
     min_sdk_version: "29",
+    target: {
+        darwin: {
+            enabled: false,
+        },
+    },
 }
 
 // These interfaces are android-specific implementation unrelated to binder
@@ -122,6 +127,9 @@
         vendor: {
             exclude_srcs: libbinder_device_interface_sources,
         },
+        darwin: {
+            enabled: false,
+        },
     },
 
     aidl: {