fix: align ndk with android app

[ovitrif]

Parent: synonymdev/bitkit-android#1190

Problem

Bitkit Android uses r28b / 28.1.13356709. The LDK Android publication workflow requests r28c but leaves the runner's r27d ANDROID_NDK_HOME conflicting with ANDROID_NDK_ROOT, so published 0.7.0-rc.64 used r27d.

Scope

• Change the Android publication configuration to r28b / 28.1.13356709.
• Set ANDROID_NDK_HOME and ANDROID_NDK_ROOT to that NDK path.
• Publish a new immutable LDK Node Android package for integration in Bitkit Android.