Add native_bridge target to Android.bp

This allows us to build guest libraries for the native bridge for
arm/arm64 architectures.

Bug: http://b/77159578
Test: make
Change-Id: I35520ca456105ddadd456c78a4eb1e6de39147c5
diff --git a/Android.bp b/Android.bp
index 25e2796..365c5bf 100644
--- a/Android.bp
+++ b/Android.bp
@@ -444,6 +444,7 @@
     defaults: ["linux_bionic_supported"],
     vendor_available: true,
     recovery_available: true,
+    native_bridge_supported: true,
 
     arch: {
         arm: {
@@ -466,6 +467,7 @@
     defaults: ["linux_bionic_supported"],
     vendor_available: true,
     recovery_available: true,
+    native_bridge_supported: true,
 
     arch: {
         arm: {