Mirror of MobDev.NdkVersion's @recommended constant.

mob_new ships as a Mix archive and cannot depend on mob_dev at project-generation time, so the recommended NDK version has to be duplicated here to feed into the generated android/app/build.gradle template.

A drift test (test/mob_new/ndk_version_test.exs) asserts this stays in lockstep with MobDev.NdkVersion.recommended/0 by reading the source file at ../mob_dev/lib/mob_dev/ndk_version.ex. When you bump the NDK there, bump it here too — CI will catch it if you forget.

See ~/code/mob_dev/lib/mob_dev/ndk_version.ex for the rationale (libc++ inline-namespace ABI mismatch between NDK 25 and 27).