androidenv.ndk-bundle: use jdk_headless instead of jdk

ndk-build only needs java/javac, not GUI capabilities.
Switching to jdk_headless drops ~257 MB of unnecessary
desktop dependencies (GTK+3, icu4c, harfbuzz, cups, systemd)
from the closure.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkgs/development/mobile/androidenv/ndk-bundle/default.nix

@@ -24,7 +24,7 @@ let
         gawk
         gnugrep
         gnused
-        jdk
+        jdk_headless
         python3
         which
       ]