adb: win32: fix adb_test.

At some point between Q and master, adb_test.exe stopped working because
it wasn't being linked with -municode?

Test: wine adb_test.exe
Change-Id: I6c20f3b3241cee2052d31d1ca85b8a9738828f6e
diff --git a/adb/Android.bp b/adb/Android.bp
index f6aede8..ef5057a 100644
--- a/adb/Android.bp
+++ b/adb/Android.bp
@@ -221,6 +221,7 @@
     target: {
         windows: {
             enabled: true,
+            ldflags: ["-municode"],
             shared_libs: ["AdbWinApi"],
         },
     },