Mark libbrillo as recovery_available for update_engine_sideload

Test: build update_engine_sideload
Change-Id: I317df5338fe7e8377a9f5d416cc09a99e8d79bc1
diff --git a/Android.bp b/Android.bp
index b1f5680..1ac5e95 100644
--- a/Android.bp
+++ b/Android.bp
@@ -134,6 +134,7 @@
 cc_library {
     name: "libbrillo",
     host_supported: true,
+    recovery_available: true,
     srcs: libbrillo_core_sources,
     shared_libs: libbrillo_shared_libraries,
     static_libs: [
@@ -203,6 +204,7 @@
     export_include_dirs: ["."],
 
     host_supported: true,
+    recovery_available: true,
     target: {
         darwin: {
             enabled: false,